Speaking from Trump Tower in New York, the billionaire tycoon said: "In many ways, this is the right time for the project. It's the right time to start thinking about jobs and it's the right time to start buying."
His confident vow came after the Scottish Government gave the go-ahead yesterday to the controversial development, a decision that sparked outrage among environmentalists.
John Swinney, the finance secretary, who approved the proposal, said it would have "a significant economic and social benefit".
But environmental groups said the damage to the local area was "too high a price to pay for the claimed economic benefits from this development".
The proposal for a 1 billion resort at the Menie Estate, near Balmedie, Aberdeenshire, was rejected in controversial circumstances by Aberdeenshire Council last year, before being "called in" by ministers.
The plan includes proposals for two golf courses, a 450- bedroom hotel and housing, as well as holiday apartments and golf villas.
The scheme faced strong local opposition, as well as from environmental campaigners, but won widespread support in the business community.
Last night, Alex Salmond, the First Minister, said: "The economic and social benefits for the North-east of Scotland substantially outweigh any environmental impact."
Mr Trump said now was the ideal time to start work on the project.
"It's sort of the anti-trend, and I have always been a believer in that and it's worked for me," he said.
"You start things when things are worst. As I have often said, because of the quality of the land we are given to work with, we will build the greatest golf course in the world."
Mr Trump has spent more than two years championing his vision of transforming the protected stretch of sensitive coastline into a dream golf resort, in the face of a massive outcry from environmentalists who claim it will destroy the "jewel in the crown" of Britain's shifting sand-dune systems.
Campaigners claim government approval of the scheme contravenes almost every planning and environmental policy and government strategy in the national canon.
The back nine holes of the main championship course will be laid out within the shifting sand dunes in the Foveran links site of special scientific interest.
But Mr Trump said last night: "We will stabilise the dunes. They will be there for ever. This will be environmentally better after it (the course] is built than it is before."
Mr Trump said he was determined to start work on the initial phase of the project – the golf courses – as soon as detailed approval is granted. "It could take a little time, but it will be nothing like the process we've been through. The big job has been done now.
"I would love to say we would be ready to play in less than two years on the golf course itself. We would like to start as soon as practicable," he said.
He insisted finance was not an issue, even with the world economy in the grip of a credit crunch. "The world has changed financially and the banks are all in such trouble, but the good news is that we are doing very well as a company and we are in a very, very strong cash position," he said.
"Fortunately, I haven't been a stock market person, so I was wasn't affected by the stock market. I don't even have a mortgage on the land. I bought it for cash, and that makes life much easier when you can do business that way."
The decision to grant outline planning permission was taken by Mr Swinney after a public inquiry.
The three planning reporters who conducted the inquiry concluded the significant economic and social benefit to be gained from the project outweighed the environmental impact.
Mr Swinney said: "This is a development which has been a long time in the planning and, from all of the indications, we know has been something to which the Trump Organisation has been seriously committed for many years.
"We are now in a position where we can see that development taking its course and what's important is that the decision I have arrived at today gives a clear signal to the international community that in these difficult economic times, Scotland is open for business."
But the decision to give the green light to the scheme sparked a renewed outcry by environmental groups and other opponents of the scheme.
Councillor Martin Ford, the former convener of Aberdeenshire Council's planning authority who controversially used his casting vote a year ago to reject the Trump application, claimed Mr Swinney's decision meant that a "billionaire's vanity project had been put ahead of the protection of Scotland's natural heritage".
Aedan Smith, RSPB Scotland's head of planning and development, said: "(We are] surprised and extremely disappointed at this decision, which we believe is wrong both for Aberdeenshire and for Scotland.
"We, and the thousands of other objectors, consider that this is too high a price to pay for the claimed economic benefits from this development.
"It appears the desires of one high-profile overseas developer, who refused to compromise one inch, have been allowed to override the legal protection of this important site, and we fear this sets a precedent which will undermine the whole protected-sites network in Scotland."
Jonny Hughes, the head of policy at the Scottish Wildlife Trust, was also disappointed. "This is a huge blow for the environment and sustainable development," he said.
However, many local politicians welcomed the scheme's approval.
Mr Salmond, who is also the local constituency MSP, said: "In tough economic times, substantial investment of this kind is at a premium. Six thousand jobs, including 1,400 which will be local and permanent, is a powerful argument. It is entirely right and proper that the resources of the country are harnessed to boost one of our great industries, and tourism is a great Scottish industry."
Councillor Anne Robertson, the leader of Aberdeenshire Council, said: "I truly believe this will bring significant benefits to the area, particularly in terms of jobs and tourism."
And Councillor Kate Dean, the leader of Aberdeen City Council, said: "This is absolutely the right decision for the area. This development will draw people from all over the world."
Swings and roundabouts on way to 'the world's greatest golf course'
• 12 JANUARY, 2006: It emerges that Donald Trump's aides are in talks with officials from Aberdeenshire Council, rumoured to be over the creation of a major leisure development in Scotland.
• 27 JANUARY, 2006: Ashley Cooper, managing partner of Trump Golf Properties, confirms plans to build a 1 billion golf course at Aberdeenshire's Balmedie and Hazlehead Park have stalled and Ireland is now a possible location.
• 28 APRIL, 2006: Mr Trump flies in to Aberdeen to announce plans to construct the "world's greatest golf course" at the Menie Estate, near Balmedie.
• 20 NOVEMBER, 2007: The application is thrown out by Aberdeenshire Council's planning authority on the casting vote of its chairman, Martin Ford.
• 4 DECEMBER, 2007: The Scottish Government calls in the application after Mr Trump announces he will not appeal the council decision.
• 12 DECEMBER, 2007: Mr Ford is removed from his post, following a vote of no confidence at a full meeting of Aberdeenshire Council.
• 10 MARCH, 2008: The Scottish Government announces a public local inquiry will begin in June at the Aberdeen Exhibition and Conference Centre.
• 13 MARCH, 2008: The parliament inquiry into the saga says the First Minister, Alex Salmond, took a "cavalier" approach to his involvement with the application.
• 14 MAY, 2008: The Trump Organisation makes changes to its plans. Mr Trump's team says the move takes account of the environmental impact on sand dunes. RSPB Scotland welcomes the change, but describes it as a mere "tweak" to the original plans.
• 10 JUNE, 2008: Inquiry gets under way. Mr Trump is called as the first witness.
• 15 OCTOBER, 2008: The public local inquiry report is received by John Swinney, the finance secretary, who announces a decision will be made within 28 days.
• 3 NOVEMBER, 2008: The Scottish Government announces outline planning permission has been granted.
How safe are our wild places?
FIRST things first – we're not anti-development, we're not anti-golf, and we're not anti-Trump.
We believe in sustainable development to make Scotland both wealthier and greener, which is why we're surprised and disappointed with the Scottish Government's decision to allow this development to go ahead on an unparalleled, supposedly protected Site of Special Scientific Interest (SSSI).
The government promised a "greener Scotland" as one of the five main planks in its vision for the country. We've praised much of what they've done for the environment, including an ambitious climate change bill and sustainable flooding and marine bills. But it's hard to see just how this decision can be made in a "greener Scotland".
The sad thing is that John Swinney didn't have a simple "yes or no" decision to make. We offered up a "yes but" alternative. We commissioned a respected Scottish golf course designer to come up with a different design on the site which avoided the most sensitive land.
Unfortunately, Trump International Golf Links Scotland (TIGLS) refused to compromise throughout, or even consider our "yes but" option – and now the Scottish Government seems to have followed suit. Our alternative could have brought all the economic benefits without such massive environmental damage. By ignoring it, it appears that the government has succumbed to knee-jerk political and business lobbying.
What is the point of having a network of protected areas if they're not actually protected? Will this set a dangerous precedent where, if the scale of your development is grand enough, all of Scotland is up for grabs?
The government now has a job to win back its environmental credentials. It will need to confirm that this is a truly unique case, and not a precedent that says money talks. It will need to make clear that it does indeed value our special wild places for what they are.
The diggers will soon move in and stabilise the dynamic sand dunes at Menie, and one of the best examples of such a landscape in western Europe will be lost. The inquiry report made clear the loss of dynamism cannot be mitigated, so we can cross Foveran Links SSSI off the list of "protected" sites in Scotland.
The question for now is whether our other protected areas are safe in this government's hands?
Lloyd Austin is the Head of Conservation Policy for RSPB Scotland.
Still a few hazards to avoid on the way to clubhouse
DONALD Trump has so far only been granted outline planning approval for his 1 billion golf resort in Aberdeenshire.
The Trump Organisation will now have to submit detailed plans for the development to Aberdeenshire Council before work can begin on the project.
That could be done in as little as three months. Mr Trump has made it clear that the first phase of the scheme will involve the construction of the two golf courses, expected to cost in the region of 10 million.
Anne Robertson, the leader of Aberdeenshire Council, said: "Before the development can proceed, further applications which contain the full details will have to be submitted to, and approved by, Aberdeenshire Council."
The reporters who conducted the public inquiry have recommended a series of conditions which should be attached to detailed planning approval.
These include the submission of a masterplan for the whole development and a detailed environmental impact assessment.
The reporters also recommend that no private houses should be built until the first phase involving the construction of the golf course and ancillary building, including the clubhouse, practice facilities and 36 golf villas, has been completed.
The Trump Organisation is also expected to be ordered to consult with Scottish Natural Heritage on a number of mitigation plans for site.
A spokesman for SNH said: "The inquiry report clearly accepts the extent of the adverse impacts the development will have on the fragile dune system, but has concluded that in this particular case this is outweighed by social and economic benefits.
• More on the Trump development