Beijing's behaviour in South China Sea, Taiwan Strait 'aggressive': Biden

US President Joe Biden said on Saturday that China continues to "behave aggressively" in the South China Sea and Taiwan Strait and President Xi Jinping is using diplomacy to advance his country's interest.

"China continues to behave aggressively, testing this all across the region, and it's true in the South China Sea, the East China Sea, South China, South Asia and the Taiwan Straits," Biden said during the Quad Leaders Summit in Wilmington, Delaware, in comments that were carried on the event's official feed after the press was asked to leave the room where leaders from India, Japan, Australia and the United States were convening.

"We believe Xi Jinping is looking to focus on domestic economic challenges and minimise the turbulence in China diplomatic relationships, and he's also looking to buy himself some diplomatic space, in my view, to aggressively pursue China's interest," Biden said.