“We remain concerned about China’s increasingly dangerous and unlawful actions on the South and East China Seas, which have injured people, harmed vessels from Asean nations and contradict commitments to peaceful resolution of disputes,” Blinken told Southeast Asian leaders gathered in Laos.

“The US will continue to support freedom of navigation and freedom of overflight in the Indo-Pacific,” he said.

Blinken said that the US also hoped to work with Asean leaders to “protect stability across the Taiwan Strait”, where tension has risen again as China this week denounced remarks by the self-governing democracy’s president.

Blinken is representing the US at the annual Southeast Asian meeting, where China has heard directly from leaders of concern about the dispute-rife South China Sea.

The Philippines has been alarmed by violent incidents as Beijing exerts its claims in the strategic waterway.

Another prominent theme at the summit is Myanmar, whose military junta sent a representative to the Asean meeting for the first time in more than three years. Myanmar’s delegation joined the meeting with Blinken but it was unclear if there was any direct interaction.

Blinken said he wanted to discuss the “deepening crisis in Myanmar” – a rare US usage of the country’s official name and not the former Burma.

Blinken also urged firmness against Russia’s “war of aggression” in Ukraine, ahead of a full East Asia Summit in which Russian foreign minister Sergei Lavrov will participate.