John Healey has declared that Britain will be “democracy’s most reliable ally around the world” as he laid out the Government’s plan for this week’s Nato summit in Washington DC.

Mr Healey, the Defence Secretary, joked that just days ago he had been in a “sports hall in Rotherham” before leaving the UK for a trip to Ukraine and then the US.

Thirty-two Nato member states are gathered in Washington for the 75th anniversary of the alliance this week.

Sir Keir Starmer, the prime minister, will use the summit to set out Labour’s defence strategy, including a new defence review and more support for Ukraine.

Speaking at the British Ambassador’s residence on Tuesday night, Mr Healey said the public had “given us a mandate to serve them and serve our country”.

“We’re getting on with the job in government,” he said.

“You will see this week that Keir Starmer leads our determination.

“Our determination that Britain will step up our support for Ukraine, that we’ll fulfil our Nato commitments, secure our role as Europe’s leading nation in Nato and make Britain democracy’s most reliable ally around the world.”

He said that Labour was the “party of Nato”, pointing to the work on the original Nato treaty conducted by a Labour foreign secretary, Ernest Bevin.

At the summit, member states are expected to give further detail on how Ukraine can become a member of the Nato alliance, but stop short of agreeing a specific timeline.

Nato countries are also expected to sign up to new civil defence measures to protect their infrastructure from Russian attacks.

Mr Healey said the alliance was “bigger, stronger, more united than ever” and showed “growing indivisibility” in the face of Russian aggression.

The summit could be the last one helmed by Joe Biden on behalf of the US, with Donald Trump odds-on to replace him in November’s presidential election.

In a speech on Tuesday evening, Mr Biden said Nato would send “dozens” of air defence systems to Ukraine, and that the alliance “can and will stop Vladimir Putin”.

Trump has been more critical of US support for Kyiv, pledging to end the war “in one day” through negotiations.

Sir Keir and Mr Biden are expected to meet at the White House on Wednesday.

He is expected to use the summit to call for other countries to boost defence spending to 2.5 per cent of GDP — a target the UK has not yet reached.

The current Nato defence spending target is two per cent, and some countries including Canada have come under fire for failing to reach it.