President Donald Trump has said the US will no longer tolerate “chronic trade abuses”, in a defiant address at the Asia-Pacific Economic Co-operation (Apec) summit in Vietnam.
He said the US was prepared to work with Apec countries as long as they “abide by fair reciprocal trade”.
Mr Trump said free trade had cost millions of American jobs, and he wanted to redress the imbalance.
He has already visited China and Japan as part of a five-nation Asia tour.
Apec brings together 21 economies from the Pacific region – the equivalent of about 60% of the world’s GDP.
Since taking office, President Trump has pulled the US out of the Trans-Pacific Partnership, a major trade deal with 12 Apec member countries, arguing it would hurt US economic interests.
Chinese President Xi Jinping was also addressing the summit in the Vietnamese port city of Da Nang.
In his speech on Friday, President Trump railed against the World Trade Organization, which sets global trade laws, and said it “cannot function properly” if all members do not respect the rules.
He complained about trade imbalances, saying the US had lowered market barriers and ended tariffs while other countries had not reciprocated. “Such practices hurt many people in our country,” he told business and political leaders at the summit.
But he did not lay the blame on Apec countries, and instead accused earlier US administrations of not acting earlier to reverse the trend.
He said America would make bilateral agreements with “any Indo-Pacific partner here who abides by fair reciprocal trade”, but only “on a basis of mutual respect and mutual benefit”.
The US president had travelled to Da Nang from Beijing, where he had also discussed America’s huge trade imbalance with China. There too, he said he did not blame the country for “taking advantage”.
The total trade relationship between the US and China was worth $648bn last year, but trade was heavily skewed in China’s favour with the US amassing a nearly $310bn deficit.
Mr Trump has in the past accused China of stealing American jobs and threatened to label it a currency manipulator, though he has since rowed back on such rhetoric.
China said on Thursday it would further lower entry barriers in the banking, insurance, and finance sectors, and gradually reduce vehicle tariffs.
Mr Xi promised “healthy” and “balanced” economic and trade relations.
Deals worth $250bn (£190bn) were also announced, although it was unclear how much of that figure included past agreements or potential future deals. At the same time, US Secretary of State Rex Tillerson told journalists the deals were “pretty small” in terms of tackling the trade imbalance.
Before the Beijing talks, Mr Trump in Tokyo lashed out at Japan, saying it “has been winning” on trade in recent decades.
Japanese Prime Minister Shinzo Abe will also be making a speech at the Apec summit. Japan had a $69bn (£52.8bn) trade surplus with the US in 2016, according to the US Treasury department.
As one of the first leaders to make a speech on Friday, New Zealand Prime Minister Jacinda Ardern said climate change was “the biggest challenge of our generation”.
“It is also the greatest challenge facing the Asia Pacific region,” she said, two weeks after having assumed office.
“We have the largest number of climate vulnerable people in the world. We are already seeing the terrible effects of climate change in our region. It is literally lapping at our feet.”
After attending the Apec summit, Mr Trump will pay a state visit to the Vietnamese capital Hanoi.
Mr Trump will end his 12-day Asian tour in the Philippines on 13 November.