Danang, Vietnam: President Donald Trump has warned the United States will no longer tolerate "chronic trade abuses" and would insist on fair and equal trade policies in a defiant speech to Pacific Rim countries in Vietnam.

Delivering the keynote speech at the 21-nation Asia Pacific Economic Cooperation leaders summit, Mr Trump said he won't allow the US to be "taken advantage of anymore."

He vowed to correct the US's huge trade imbalance with China and Japan.

"I will always put America first," he said.