The Prime Minister said the UK “stands ready” to support allies who have fighter jets ready to hand over to Ukraine immediately.

Rishi Sunak made the comments after undertaking a diplomatic blitz in Munich on Saturday as he looked to shore up support for Kyiv.

The UK has refused to commit to providing Royal Air Force aircraft to Ukrainian president Volodymyr Zelensky’s forces, with the Prime Minister only saying he has not ruled it out.

But the Conservative Party leader said he would back allies who are in a position to supply war planes now.

The Prime Minister told broadcasters: “We will happily provide assistance to any country that is able to provide Ukraine with fighter jets right now.

“The UK stands ready to support those countries as well.”

Downing Street used a visit by Mr Zelensky to Britain last week to announce that the Ministry of Defence would train Ukrainian pilots on Nato-standard aircraft.

Despite No 10 opening the door to potentially sending jets to Kyiv, Defence Secretary Ben Wallace has said the move could be years away, if it happens at all.

Some experts have suggested RAF aircraft are ill-equipped for the warfare being seen in eastern Europe, while also being complicated by needing other countries to sign-off on the move.

Mr Sunak also said it is “entirely reasonable” for NATO to provide long-range weapons that would help Ukraine “have a counter-offensive that moves Russia outside of its own country”.

Asked whether the UK would send weapons that could hit Russian-annexed Crimea, he added: “Those are all the things that will allow Ukraine to defend itself and repel Russian aggression.

“And, indeed, yes, to have a counter-offensive that moves Russia outside of its own country.

“I think that’s entirely reasonable and we should be fully behind Ukraine in that ambition, and want that ambition to succeed.”

He added: “We have a moment and for everyone who says we want Ukraine to win and Russia must fail – if you believe that, then you must act now.

“Because now is the moment to accelerate and increase supplies of, as I have said, those four key things – longer-range weapons, artillery, armoured vehicles and air defence.

“Those are the critical things we need now and that’s how we’re going to turn this thing around and ensure Ukraine does win.”