US President Donald Trump and his China counterpart Xi Jinping./XINHUA

The bilateral talks between US President Donald Trump and his China counterpart Xi Jinping have ended. They lasted about two hours, double the duration originally scheduled.

In his opening remarks, Trump says it is "an honour" to be meeting Xi today. "We've gotten along, when there were difficulties, we worked it out. I would call you and you would call me," Trump says.

"People don't know; whenever we had a problem, we worked it out very quickly."

"I say it to everybody: you're a great leader," Trump says. The US president said he's brought the "best [business leaders] in the world" with him on this trip.

"Only the top people here today to pay respects to you," he says.

Trump adds that some people have called this "the biggest summit ever", and that he looks forward "very much" to their discussions.

"It's an honour to be with you; it's an honour to be your friend," he says, adding that US-China relations are going to be "better than ever before".

Later this evening, Trump is set to take part in a state banquet held in his honour. The US president has since arrived at the Temple of Heaven, an ancient complex of temples in Beijing and a major tourist attraction. Trump was expected to visit the temple this afternoon with Xi.

The complex announced two days ago that it will be closed to the public today.

Trump and Xi were deep in talks behind closed doors as the bilateral discussions overran for some 30 minutes, taking into account the fact that they started late.

Xi will now meet with US business leaders following the two-hour bilateral talks between both presidents. He says China's door will only open wider to US businesses, adding that American firms will have broader prospects in the country.

He also says American companies have been deeply involved in China's growth, which has benefited both sides, adding that Beijing welcomes the US to strengthen reciprocal cooperation, according to Chinese state media, Xinhua.

Trump has brought with him a delegation comprising more than a dozen top business executives, including Nvidia's Jensen Huang and Tim Cook from Apple, raising hopes for new deals. The US president has been pushing China to buy more American goods.

In the talks President Xi warned of the potential for "conflict" with the US over Taiwan, Chinese state media reported, with the leader reportedly calling it the "most important issue in China-US relations".

"If it is handled well, bilateral relations can remain generally stable. If it is not handled properly, the two countries could collide or even come into conflict, pushing the entire China–US relationship into a very dangerous situation," Xi says, according to state media.

He adds that Taiwan independence is "fundamentally incompatible" with peace in the Taiwan Strait. And peace in the strait is the "greatest common ground between China and the United States", he says.

Taiwan is a key topic of discussion between the two superpowers – and Taipei is watching the Trump-Xi meeting very closely.

Asked about the summit in Beijing, Taiwanese government spokesperson Michelle Lee says they are grateful for the United States' repeated affirmation of its support for Taiwan, Reuters reports.