Top US and Chinese diplomats met in New York on Friday as rising tensions show signs of easing, but Beijing issued a fresh warning against supporting Taiwan.

Foreign Minister Antony Blinken and Chinese Foreign Minister Wang Yi shook hands but only exchanged pleasantries in front of the cameras before sitting down with aides on the sidelines of the annual United Nations summit.

It was their first meeting since extensive talks in Bali in July, during which both sides seemed optimistic about more stability.

A month later, House Speaker Nancy Pelosi visited Taiwan and enraged Beijing, which was staging drills seen as a dry run for an invasion of self-governing democracy.

In a sign of smoother relations, Wang also met with US climate envoy John Kerry in New York, although China announced after Pelosi’s visit that it would limit cooperation on the issue, a key priority for Biden.

Blinken continued talks despite cutting his schedule after his father’s death on Thursday. Immediately before meeting Wang, he met with his peers from Australia, Japan and India, the so-called “Quad,” which Beijing denounced as an attempt to isolate it.

“Our four countries know very well the great challenges we face as well as the opportunities that lie ahead, and more than ever they demand that we work together,” said Blinken, as ministers signed an agreement on cooperation in disaster relief signed.

President Joe Biden said in an interview that aired Sunday that he stands ready to intervene militarily if China uses force in Taiwan, deviating again from decades-long US ambiguity.

In a speech ahead of his talks with Blinken, Wang reiterated his anger at US support for Taiwan, which China considers part of its territory.

“The Taiwan issue is emerging as the greatest risk in China-US relations. If mishandled, it will most likely destroy bilateral ties,” he said at the Asia Society think-tank.

“Just as the US will not allow Hawaii to be taken away, China has the right to maintain the country’s unification,” he said.

He condemned the US decision to “allow” Pelosi, who is second in line to the presidency after the vice president, to visit Taiwan. The Biden administration, while privately concerned about her trip, noted that Congress is a separate branch of government.

But Wang was forgiving towards Biden. The New York talks are expected to lay the groundwork for a first meeting between Biden and President Xi Jinping since they became leaders of their two countries, likely in Bali in November on the sidelines of a Group of 20 economic powerhouse summit.

Wang said that both Biden and Xi are committed to “making China-US relations work” and “avoiding conflict and confrontation.”

The US Congress is a stronghold of support for Taiwan, a vibrant democracy and great technological power.

Last week, a Senate committee took a first step to ship billions of dollars worth of arms directly to Taiwan in a bid to deter China, a rise from decades of selling only arms requested by Taipei.

Tensions have also risen over human rights, as the United States accuses the communist state of committing genocide against the predominantly Muslim Uyghur population.

Biden, like his predecessor Donald Trump, has viewed a rising China as the United States’ key global competitor and has promised to realign US foreign policy to the challenge.

Russia’s invasion of Ukraine in February quickly shifted US focus to Europe, but it also fueled fears that Beijing was realizing years of threats to use force against Taiwan.

However, US officials were also heartened that China has shown some distance from Russia, its nominally close ally.

Meeting in New York with Ukraine’s foreign minister for the first time since the war, Wang stressed the need for a ceasefire rather than support for Russia at a Security Council meeting on Thursday.