Sir Keir Starmer held talks with Donald Trump on a visit to New York on Wednesday but he failed to secure a meeting with Kamala Harris.

The Prime Minister met with the former president for the first time at Trump Tower in an attempt to establish relations with him ahead of the US election.

He had also hoped to meet Ms Harris, the Democrat candidate, but said that “diary challenges” had meant it was not possible to do so.

Sir Keir was in New York for the UN General Assembly, where he gave a speech denouncing Russia’s invasion of Ukraine.

He held a meeting with Trump hours after the Republican nominee gave his strongest signal yet that he would scale back support for Kyiv.

Before the talks, Sir Keir said: “It’ll be really to establish a relationship between the two of us. I’m a great believer in personal relations on the international stage.

“I think it really matters that you know who your counterpart is in any given country, and know them you know personally, get to know them face to face.

“Obviously, I still want to speak to Harris as well. But you know, the usual diary challenges, but it’s good that this one now has been fixed.”

Sir Keir was asked whether he would be prepared to stand up to Mr Trump if he becomes US president again on global issues including Ukraine.

The Republican candidate criticised Volodymyr Zelensky, the Ukrainian president, on Wednesday and said Kyiv should have “given up a little bit” to appease Vladimir Putin.

“We continue to give billions of dollars to a man who refuses to make a deal, Zelensky,” he said at a campaign event in North Carolina.

Asked whether he would confront Trump over his views, Sir Keir said: “The first thing I think is important to say in relation to this is we’ve obviously had a special relationship with the US for a long time, forged in really difficult circumstances.

“That always sits above whoever holds the particular office, either in the US or the UK, and it is really important.

“I think it’s probably as strong now as it’s ever been, in relation to the Middle East and Ukraine.”

He added: “The US people will decide who they want as their president, and we will work with whoever is president, as you would expect.”

Sir Keir was set to leave Washington on Friday night without any announcement on allowing Ukraine to fire long-range missiles into Russia.

He held talks with Joe Biden in the White House to discuss letting Ukraine use the UK’s Storm Shadow missiles.

But John Kirby, a spokesman for the US national security council, said there would be no announcement on the issue after the meeting. He did not rule out one at a later date.