Washington: US President Donald Trump is ready to meet North Korean leader Kim Jong-un again for denuclearisation talks, the White House said, underlining that his decision to walk out of the Hanoi summit sent a signal to other countries as well that he is not desperate for a deal unless it is in America's interest.

US National Security Advisor John Bolton told ABC News that Trump's walk out from his meeting with Kim was "friendly" and it is not a reflection that the talks broke down.

I don't really think it broke down. I think the president did exactly the right thing, he said, referring to the failed summit between the two leaders in Hanoi in Vietnam on February 26 and 27.

Trump and Kim's Vietnam meeting ended abruptly without a deal on North Korean denuclearisation in return for sanctions relief.

On Friday, Trump told reporters his relationship with Kim was a very good one and said he would be surprised in a negative way if he did anything that was not per our understanding.

Trump and Kim first met in Singapore in June 2018, producing only a North Korean commitment to work towards complete denuclearisation of the Korean peninsula.

"Trump and Kim Jong-un had had a number of conversations about what might be done to denuclearise North Korea. Kim offered a partial deal. The president has been very clear that he doesn't want to make the same mistakes as past administrations, Bolton said.

"Trump proposed to Kim what he talked about really going back to Singapore, is what he called the big deal, that North Korea completely denuclearize. And, in exchange for that, there was a very bright economic future for the North Korean people," Bolton said.

The two leaders went around on this several times. They had a full exchange of views, as the saying goes. It was clear they weren't going to reach agreement, Bolton said.

So, what the president did was, as he put it, to walk away in a friendly way from the discussion. He said he's prepared to meet Kim Jong-un again. It's no date set or anything like that, but it's possible that North Korea will go back and rethink the position they came in with and come back to talk to the president about the big deal, he told the news channel in a talk show.

According to Bolton what the president did in Hanoi, was important not just in the negotiations with North Korea on their nuclear programme, but also with China on trade, and also with Russia on arms control and other countries.

Despite all the media speculation, the president turned out not to be desperate for a deal. He didn't have to come away with a success. In the pursuit of American national interest, he was prepared to risk people characterising the Hanoi summit as a failure, because he wasn't going to accept terms that weren't in our national interest, he said.

I do think that's a message for others that we're involved in significant negotiations with. Now, in terms of China specifically, you know, we just concluded another round of negotiations here in Washington, Bob Lighthizer, the U.S. trade representative, Steven Mnuchin, the treasury secretary, and others leading that, he said.

Talks with China are making progress, but there's work to be done. So it's true, as you say, there's no date set for the next summit, but it could be just a short time thereafter. We're going to have to have some more conversations and do the additional work, Bolton said