The Prime Minister made the declaration as he was addressing a Scottish reception at the Conservative Party conference in Manchester yesterday.
Pledging to unite the UK after delivering Brexit on 31 October, Mr Johnson promised he would drape a Union flag around COP26 - the UN climate change conference that Glasgow has won the hosting rights for in November next year.
The PM said: "I don't mind seeing a Saltire or two, but I want o see the Union flag and I don't want to see Nicola Sturgeon anywhere near it.
"The Scottish Nationalist Party didn't secure that summit in London. It was the United Kingdom government.
"Let's expose the frauds of the SNP who bleat endlessly on about their desire to smash up the oldest and most successful political union and political partnership anywhere in the world simply to cover up their domestic failures, their high taxes, their inability to run a successful health or education system."
A spokesman for Ms Sturgeon told The Times: "Boris Johnson certainly sounded like he was enjoying himself at the Tory drinks reception, but out in the real work people will be deeply embarrassed to hear their prime minister acting so childishly.
"It is right that the COP26 conference should come to Scotland given our leadership in climate action. We were one of the first countries in the world to acknowledge the global climate emergency and the Scottish Government has introduced the toughest targets in the UK to ensure our action matches the scale of our climate ambitions."
Conservative MPs have warned Mr Johnson his language is harming the chances of getting a Brexit deal through the Commons.
Ms Sturgeon is due to meet with Labour leader Jeremy Corbyn today, alongside other opposition party leaders, to discuss the hope of brokering a government of national unity and installing a temporary prime minister in place of Mr Johnson.
Scottish Tories leader Jackson Carlaw used the Scottish reception to launch a blistering attack against his own opponents in a declaration to "bury the SNP".
He said Ms Sturgeon's willingness to back Mr Cobyn as an interim prime minister was an "absolute disgrace".
Mr Carlaw also dubbed Liberal Democrats leader Jo Swinson as "Scotland's very own pound shop Mary Poppins".