The Labour leader said he would order an immediate strategic defence review covering “all aspects” of defence policy if he won the general election on June 8.
His comments appeared to row back on an agreement announced at last year’s party conference that it would back renewal of the deterrent despite Mr Corbyn’s life-long opposition to nuclear weapons.
But in a statement issued less than two hours after his appearance on BBC1’s The Andrew Marr Show, a party spokesman said: “The decision to renew Trident has been taken and Labour supports that.”
The Conservatives seized on the confusion to say Labour was in “chaos” and could not be trusted with the nation’s defences.
In his interview, Mr Corbyn declined to say whether the party still backed Trident.
Asked whether it could be cancelled under Labour, he said: “We will have a strategic defence review immediately which will include all aspects of defence. We would then look at the situation at that time.”
Pressed on whether it would be in Labour’s election manifesto as the party’s shadow defence secretary Nia Griffith had previous promised, he said: “We haven’t completed work on the manifesto yet.
“We are having that discussion in the Labour Party and we will produce our manifesto early in May.”
His words threatened to reopen the bitter divisions within Labour after he was forced to abandon his attempts to persuade the party to back his support for unilateral disarmament in the face of opposition from the trade unions.
“I have made clear my views on nuclear weapons. I have made clear there would be no first use of it. I have made clear that any use of it would be a disaster for the whole world,” he said.
Asked what he would say in the “letters of last resort” written by prime ministers with their final instructions to the commanders of Britain’s four Trident submarines, he said only: “A strict instruction, follow orders when given.”
He was immediately accused by the Conservatives of preparing to “dismantle” Britain’s defences.
Mr Corbyn faced further controversy when he suggested he would be reluctant to order a drone strike to take out the leader of Islamic State (IS) Abu Bakr al-Baghdadi if British intelligence discovered his whereabouts.
“I think the leader of Isis not being around would be helpful. I am no supporter or defender in any way whatsoever of Isis,” he said.
“But I would also argue that the bombing campaign has killed a large number of civilians who are virtually prisoners of Isis so you have got to think about these things.”
He also suggested he could suspend RAF air strikes on IS in Syria and Iraq, and said he would urge US President Donald Trump to resume international peace talks on Syria in Geneva.
He refused to be drawn on whether he would insist on the end of the free movement of labour with the European Union in the Brexit negotiations.
Home Secretary Amber Rudd said: “This morning we learnt that Jeremy Corbyn would refuse to strike against terrorists, dismantle our nuclear defences and fail to control our borders,”she said.
“Unless people turn out and vote Conservative, this man could be our prime minister in less than seven weeks’ time.”