US President Joe Biden said after a summit with Xi Jinping on Wednesday that he still considers the Chinese president a "dictator", after he sparked fury from Beijing by making the comparison earlier this year.

"Well look he is, I mean he's a dictator in the sense that he's a guy who's running a country, a Communist country, that's based on a form of government totally different than ours," Biden said at the end of a news conference when a reporter asked if he would still use the term to describe Xi.

US President Joe Biden and Chinese President Xi Jinping agreed to restore military communications at their first summit in a year Wednesday, even as Biden went off script by saying he still considered Xi a "dictator."

The leaders shook hands and strolled in a garden at a historic California estate during four-hour talks aimed at preventing growing tensions between the world's largest economies from spiraling into conflict.

They also agreed that China would crack down on the production of ingredients for the drug fentanyl, responsible for a deadly epidemic of opioid abuse in the United States.

But Xi and Biden remained far apart on the wider flashpoint of Taiwan, with the Chinese president telling his US counterpart to stop arming the island and saying that reunification was "unstoppable."

Beijing claims sovereignty over the self-ruling democracy and has not ruled out seizing it by force.

The two leaders had not met in person since they held talks in Bali in November 2022, and relations nosedived after the United States shot down an alleged Chinese spy balloon in February this year.

But Biden told a press conference at the Filoli estate in California that his talks with Xi, whom he has known since 2011, were "some of the most constructive and productive discussions we've had."