Leaders of the 21-nation Asia-Pacific Economic Cooperation (APEC), including US President Donald Trump and China's President Xi Jinping, also said they would not resort to protectionist policies.

Their joint statement, after a virtual summit hosted on Friday by Malaysia, is set against a backdrop of ongoing trade tensions between the world's two largest economies.

"The impact of (the US-China) trade war has been eclipsed by the COVID-19 pandemic," Malaysian Prime Minister Muhyiddin Yassin told reporters after the meeting.

"APEC has also pledged to refrain from backtracking and resorting to protectionist measures to keep markets and borders open," he said.

In the communique, the leaders said they recognised "the importance of a free, open, fair, non-discriminatory, transparent and predictable trade and investment environment" to drive growth during the crisis.

APEC countries failed to reach agreement in 2018, after talks were stymied by discord over trade and investment between the United States and China, and last year's gathering in Chile was cancelled due to violent street protests.

Trump, who has yet to concede defeat in the November 3 US election and begin a transfer of government to President-elect Joe Biden, largely focused on domestic issues in his remarks at the meeting and spoke of the successes of his time in office, a source who heard his address said.

It was an unusually subdued performance by Trump, who has often attacked China over COVID-19, declared it a strategic rival and imposed tariffs on billions of dollars in Chinese goods.

A White House statement said Trump had "reaffirmed the commitment of the United States to building on our unprecedented economic recovery from COVID-19, as well as promoting peace and prosperity in the Indo-Pacific region through strong economic growth".

Although Trump's administration declared the Asia-Pacific and competition with China to be foreign policy priorities, he has been criticised for limited personal engagement in Asia.

The only other time he has joined an APEC summit was in 2017. He also missed a summit of the Association of Southeast Asian Nations (ASEAN) last weekend, when 15 nations formed the world's largest free-trade bloc, the Regional Comprehensive Partnership Agreement (RCEP), cementing China's dominant role in regional trade.

In his remarks on Friday, Xi called for free and open trade and investment, and support for multilateralism.

He said China would "actively consider" signing up for a regional free-trade pact, the Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP).

When he took office, Trump pulled out of the Trans-Pacific Partnership trade pact, the predecessor to CPTPP.

Other leaders who joined the virtual meeting include Australian Prime Minister Scott Morrison, New Zealand Prime Minister Jacinda Ardern, Japanese Prime Minister Yoshihide Suga, Russian President Vladimir Putin and Canadian Prime Minister Justin Trudeau.

Australian Associated Press