Donald Trump has said that he is disappointed but not done with Vladimir Putin, in an exclusive phone call with the BBC.

The US president was pressed on whether he trusts the Russian leader, and replied: “I trust almost no-one.”

Trump was speaking hours after he announced plans to send weapons to Ukraine and warned of severe tariffs on Russia if there was no ceasefire deal in 50 days.

In an interview from the Oval Office, the president also endorsed Nato, having once described it as obsolete, and affirmed his support for the organisation’s common defence principle.

The president made the phone call, which lasted 20 minutes, to the BBC after conversations about a potential interview to mark one year on since the attempt on his life at a campaign rally in Butler, Pennsylvania.

Asked about whether surviving the assassination attempt had changed him, Trump said he liked to think about it as little as possible.

“I don’t like to think about if it did change me,” Trump said. Dwelling on it, he added, “could be life-changing”.

Having just met with Nato chief Mark Rutte at the White House, however, the president spent a significant portion of the interview expanding on his disappointment with the Russian leader.

Trump said that he had thought a deal to end the war in Ukraine was on the cards with Russia four different times.

When asked by the BBC if he was done with Putin, the president replied: “I’m disappointed in him, but I’m not done with him. But I’m disappointed in him.”

Pressed on how Trump would get Putin to “stop the bloodshed” the US president said: “We’re working at it, Gary.”

“We’ll have a great conversation. I’ll say: ‘That’s good, I’ll think we’re close to getting it done,’ and then he’ll knock down a building in Kyiv.”

Russia has intensified its drone and missile attacks on Ukrainian cities in recent weeks, causing record civilian casualties. It launched a full-scale invasion of its neighbour in 2022.

Putin has insisted he also wants peace but has said what he calls the “root causes” of the war must be resolved first. He argues that the war is the result of external threats to Russia’s security from Kyiv, Nato and the “collective West”.

The conversation moved on to Nato, which Trump has previously criticised as “obsolete”.

Asked if he still thought this was the case, he said: “No. I think Nato is now becoming the opposite of that” because the alliance was “paying their own bills”.

He said he still believed in collective defence, because it meant smaller countries could defend themselves against larger ones.

Trump said that the leaders of countries including Germany, France and Spain, had come to respect him and his decision making, partly because world leaders believed that there was a “lot of talent” in being elected to the presidency twice.

When asked whether world leaders were at times “obvious in their flattery”, Trump replied that he felt they were “just trying to be nice”.

President Trump was also asked about the UK’s future in the world and said he thought it was a “great place – you know I own property there”.

On the issue of Brexit, he said it had been “on the sloppy side but I think it’s getting straightened out”.

The president also said of Sir Keir Starmer: “I really like the prime minister a lot, even though he is a liberal”, and praised the UK-US trade deal. He said he had a “special bond” with the UK and that was why he had made a deal with the country – “for the most part, in terms of your competitors and in terms of the European Union I haven’t made a deal”.

He spoke about how he was looking forward to an unprecedented second state visit to the UK in September this year.

On what he wanted to achieve during the visit, Trump said: “Have a good time and respect King Charles, because he’s a great gentleman.”

He said he would not want the UK parliament, which does not sit in September, to be recalled so he could give a speech there, saying instead that MPs should enjoy their time away: “I think let them go and have a good time.”

The president also said he had not been concerned by Charles’s speech at the opening of Canada’s parliament, in which the British monarch – who is Canada’s head of state – stressed its sovereignty after Trump had suggested the US could annex the country.

“They’re wrapped up with Canada so what’s he gonna do, you know, he has no choice,” the president said, adding: “I thought he was very good, very respectful.”

He said the US was “negotiating with Canada right now” and it was going to “work out very well”.

Turning to his domestic agenda, the president said he had done a “great job” on one of his key election pledges – tackling illegal crossings at the US-Mexico border, which have dropped to record lows in the first months of his second term.

“I’ve done actually more than the promises that I’ve made,” he said.

His administration has now shifted its focus to the identification, detention and deportation of migrants across the US who are in the country illegally.

Pushed on what level of deportations would represent a success, Trump said he would not “put a number” on it, adding: “I want to get the criminals out quickly, and we’re doing that.”

“We’re bringing them to El Salvador, lots of other places,” he said, referring to the controversial deal which saw the deportation of people the White House called gang members to a prison in the central American country.

As for the action by some courts to halt aspects of his deportation policy, he said: “We’ve won all these cases in appeal. We’ve had some judges that are radical left lunatics, and every case has been overturned.”

The Trump administration has had some success on this front, including a recent Supreme Court ruling allowing it to deport migrants to third countries.

The president also praised his landmark tax and spending bill – “the one big beautiful bill” – which extends 2017 tax cuts from Trump’s first term, as well as creating new tax breaks on tips and steep cuts to Medicaid, the state-provided healthcare scheme.

“We have the largest tax cuts in history,” he said.

Asked what he thought would define his legacy as president, he said: “Saving America.”

“I think America is now a great country and it was a dead country one year ago.”