China's President Xi Jinping urged Vietnam to join forces in upholding free trade, before wrapping up a visit to Hanoi on Tuesday which President Donald Trump said was aiming to "screw" the United States.

Xi visited Vietnam as part of a Southeast Asia tour that will include Malaysia and Cambodia, with Beijing trying to position itself as a stable alternative to Trump as leaders confront US tariffs.

The Chinese leader called on his country and Vietnam Monday to "oppose unilateral bullying and uphold the stability of the global free trade system", according to Beijing's state media.

Hours later, Trump told reporters at the White House that their talks were aimed at hurting the United States.

"I don't blame China. I don't blame Vietnam. I don't. I see they're meeting today, and that's wonderful," he said.

"That's a lovely meeting... like trying to figure out, how do we screw the........

© International Business Times