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 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 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.

The conversation moved onto 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 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."