San Francisco (AFP) - US President Joe Biden reassured Asia-Pacific economies of American commitment at a summit in San Francisco Thursday, and said his talks with Chinese leader Xi Jinping would provide stability for the region and the whole world.

"We're not going anywhere," Biden told the APEC (Asia-Pacific Economic Cooperation) group, which includes 21 members but lives under the shadow of US-China relations.

The summit opened with a sense of relief after Biden and Xi met for the first time in a year at a sumptuous villa outside San Francisco on Wednesday, and emerged pledging to avoid the kind of dangerous rift that could upend the world economy.

They agreed to restore military-to-military links and Xi promised to crack down on production of the ingredients in China for the drug fentanyl flooding into the United States.

Biden told the APEC summit that Washington was committed to the region despite Beijing's efforts to expand its influence in the region.

The US president said Xi had asked him on Wednesday "why we are so engaged in the Pacific."

"I said it's because we're a Pacific nation. Because of us there's been peace and security in the region, allowing you to grow. He didn't disagree," said Biden.

- Troubled trade deal -

Biden however said the US and China were now committed to diplomacy to avoid "surprises or bad misunderstandings" -- even if the two sides remain as far apart as ever on Taiwan, the US-backed democratic island claimed by China.

"A stable relationship between the world's two largest economies is not merely good for those two economies but for the world," he said.

With the main summit starting in San Francisco, focus broadened to the hugely dynamic area stretching from the coasts of Canada to Chile and across to Australia, China and Russia.

Biden said the talks over the next two days would focus on issues including artificial intelligence, climate resilience and supply chains, adding that the "challenges before us today are unlike those faced by previous groups of APEC leaders."

Even while insisting that the United States has no intention of "decoupling" -- cutting supply chains and effectively ending cooperation -- with China, the Biden administration is busily trying to strengthen alliances with countries in the APEC region worried about Beijing's expansionist policies.

A big plank in that platform is the Indo-Pacific Economic Framework for Prosperity (IPEF) -- a loose trade pact meant to bind together the United States and like-minded democracies such as Australia and South Korea. However, the IPEF has already hit barriers due to US domestic political opposition.

Speaking to reporters, Deputy National Security Advisor for International Economic Affairs Mike Pyle said the deal was not dead.

"President Biden will make it absolutely clear that the United States will continue to engage both diplomatically and economically in this critical region," he said. "Most trade deals take years to complete."

Pandas for peace?

The summit will come with a number of sideline bilaterals.

Mexico and China kicked off their talks on Thursday, a meeting Mexico's foreign minister this week described as "very important."

Mexican President Andres Manuel Lopez Obrador, who frequently shuns international meets, will huddle with Biden on Friday, where the two men are expected to address fentanyl, some of which comes through Mexico on its way into the United States.

Biden, for his part, said on Wednesday that despite his talks with Xi, he still considers the communist leader a "dictator" -- a remark that drew fire from the Chinese government.

Xi however received a warm reception at a dinner in San Francisco on Wednesday with hundreds of US business leaders, who rose to their feet and clapped as he entered and gave him several rounds of applause. 

The Chinese leader hinted at the dinner that he may deploy a form of soft, even cuddly power to improve ties with the United States -- pandas.

The US will soon be without any of the popular big bears after three were sent back from Washington this year.

Xi said China was considering a new batch as "envoys of friendship between the Chinese and American people."