Xi Jinping has urged Vietnam to resist “unilateral bullying” and uphold free and open trade, as he begins a high-stakes diplomatic tour of the region’s major export-reliant economies in a bid to position his country as a stable partner in contrast to the United States.

China's President Xi Jinping called on Monday for stronger ties with Vietnam on trade and supply chains amid disruptions caused by U.S. tariffs, as he attended the signing in Hanoi of dozens of cooperation agreements between the two communist-run nations.

Xi starts a three-nation tour of Southeast Asia this week, beginning his state visits with Vietnam from April 14 to 15. The trip comes with an aim to consolidate economic ties with some of China's closest neighbours at a time when the world's top two economies are locked in a tariff tussle.