• Video report by ITV News Correspondent Emma Murphy

US president Donald Trump declared relations with China were “right back on track” after he and President Xi Jinping sought to de-escalate a prolonged trade war between the economic powerhouses.

Xinhua, the Chinese state-run news agency, said that during talks at the G20 summit the leaders had agreed to a new ceasefire in a year-long trade war, adding that stalled trade talks would resume and the US would hold off on threatened additional tariffs on Chinese goods.

It came as Trump invited North Korea’s Kim Jong Un to shake hands at the Korean demilitarised zone (DMZ) when he flies to South Korea following the end of the G20 conference.

He said he also wanted to inspect the zone as an example of a "real border".

Donald Trump meets with Saudi Arabia’s Crown Prince Mohammed bin Salman Credit: Susan Walsh/AP

The apparent truce between the US and China marks a pattern for talks between Mr Trump and Mr Xi, who have professed their friendship with each other and hit the pause button on protectionist measures after their conversations, only to see negotiations later break down over the contentious details.

Taking place on the sidelines of the G20 summit in Japan, the meeting with Mr Xi marked the centrepiece of four days of diplomacy for Mr Trump, whose re-election chances have been put at risk by the trade war that has hurt American farmers and battered global markets.

Tensions rose in recent weeks after negotiations collapsed last month.

At a subsequent meeting with Turkey’s president, Mr Trump said talks with Mr Xi went “probably even better than expected”.

“The negotiations are continuing,” he said.

The meeting with Mr Xi is one of three Mr Trump had lined up on Saturday with world leaders displaying authoritarian tendencies.

Mr Trump had his first face-to-face sit-down with Saudi Arabia’s Mohammed Bin Salman since the US intelligence community concluded that the crown prince directed the killing of Washington Post columnist, and American resident, Jamal Khashoggi last year.

Mr Trump also met with Turkish president Recep Tayyip Erdogan, an ostensible Nato ally whom the US sees as drifting dangerously toward Russia’s sphere of influence.

Meeting with the Saudi crown prince, Mr Trump praised his “friend” for taking steps to open up the kingdom and extend freedoms to Saudi women.

Mr Trump, however, ignored reporters’ questions about the crown prince’s alleged role in Mr Khashoggi’s death.

Mr Trump addresses a news conference after his meeting with Mr Xi. Credit: AP

With Mr Erdogan, Mr Trump said the leaders will “look at different solutions” to Turkey’s planned purchase of the Russian-made S-400 surface-to-air missile system.

US officials have threatened that purchase would halt the sale of the US-made F-35 Joint Strike Fighter, although Mr Erdogan has called it a done deal.

“Turkey has been a friend of ours,” Mr Trump said. He blamed the Obama administration for not agreeing to sell US-made Patriot missile batteries to Turkey.

Earlier on Saturday, he took to Twitter to confirm his trip to South Korea, adding: "While there, if Chairman Kim of North Korea sees this, I would meet him at the Border/DMZ just to shake his hand and say Hello(?)!”

He later said of the invitation: “All I did is put out a feeler if you’d like to meet,” adding he was not sure of Mr Kim’s location.

“I said if Chairman Kim would want I’d meet, I’ll be at the border.”

North Korea said Mr Trump’s offer was a “very interesting suggestion”.

The North’s first vice foreign minister Choe Son Hui said that the meeting, if realised, would serve as “another meaningful occasion in further deepening the personal relations between the two leaders and advancing the bilateral relations”.

Ms Choe said North Korea had not received an official proposal for the DMZ meeting from the United States.

Mr Trump also said he wants to inspect the heavily-fortified demilitarised zone as an example of what a “real border” looks like.

Mr Trump made curtailing illegal immigration and building a wall on the US-Mexico border a central theme of his 2016 campaign, though he has struggled to fulfil his pledge.

“By the way, when you talk about a wall when you talk about a border, that’s what they call a border. Nobody goes through that border,” he said.

“That’s called a real border.”