US President Donald Trump has said he has "made no commitment either way" on Taiwan during talks with China's President Xi Jinping.

On the flight back to Washington after the two-day summit in Beijing, Trump told reporters the pair had "talked a lot" about Taiwan - a self-governing island, which China claims as part of its territory and has not ruled out taking by force.

Trump said Xi had asked directly if the US would defend Taiwan, and he had responded: "I don't talk about that."

The US president also said he would "make a determination over a fairly short period" on whether to go ahead with previously US announced arms sales to Taiwan which China has condemned.

Taiwan is a long-standing US ally and Washington is bound by law to provide the island with the means to defend itself.

Successive US administrations have walked a diplomatic tightrope by maintaining that relationship alongside building ties with Beijing.

But that balance has been increasingly tested in recent years as China has ramped up military drills around the island, raising tensions in the region, and rattling Washington.

Late last year, the Trump administration announced an $11bn ($8bn) package of weapons to be sold to Taiwan, including advanced rocket launchers and a variety of missiles.

However on Friday, Trump said he would be "making decisions" on the sale, adding that he would speak to Taiwan's President Lai Ching-te first.

"We discussed the Taiwan, you know, the whole thing with the arm sales in great detail," he said, referring to talks with his Chinese host in Beijing.

Xi "feels very strongly" about the island and "doesn't want to see a movement for independence", Trump said.

"I made no commitment either way," Trump added, without elaborating.

"The Taiwan question is the most important issue in China-US relations," Xi warned during the talks, according to Chinese state media.

"If mishandled, the two nations could collide or even come into conflict," he said.

Asked if he foresaw a conflict with China over Taiwan, Trump said: "No, I don't think so. I think we'll be fine. [Xi] doesn't want to see a war."

He added: "On Taiwan, [Xi] does not want to see a fight for independence because that would be a very strong confrontation, and I heard him out.

"I didn't make a comment on it. I heard him out. I had a lot of respect for him."

Reporters also asked Trump if the US would defend Taiwan should it come under attack.

"I don't want to say that. I'm not going to say that," Trump said. "There's only one person that knows that. You know who it is? Me."

He continued: "That question was asked to me today by President Xi... He asked me if I'd defend them. I said, 'I don't talk about that'."

Taiwan's Foreign Minister Lin Chia-lung said his team had been monitoring the US-China summit, and had maintained good communication with the US and other countries "to ensure the stable deepening of Taiwan-US relations and safeguard Taiwan's interests".

He said Taiwan had always been a "guardian of peace and stability" in the region and accused China of escalating risk with its "aggressive military actions and authoritarian oppression".

Trump and Xi toured Zhongnanhai, the heavily guarded compound where China's top leaders live and work.

Vote comes a week after lawmakers ousted the nation's former pro-China prime minister.

"It's just time," he told Fox News, adding that his resignation is effective immediately.

President Trump was welcomed by President Xi Jinping in Beijing for what will be a whirlwind tour.

The leaders of the world's two superpowers were all smiles for the cameras during the US president's visit to Beijing.