The top US diplomat is due to meet China's Wang Yi on the sidelines of an Association of Southeast Asian Nations (ASEAN) foreign ministers meeting being held in Vientiane.

Blinken has prioritized promoting a "free and open" Asia-Pacific region; a thinly veiled criticism of China's regional economic, strategic and territorial ambitions.

During a series of ASEAN meetings, "the Secretary's conversations will continue to build upon the unprecedented deepening and expansion of US-ASEAN ties", the State Department said in a statement shortly before Blinken touched down in Vientiane.

This is Blinken's 18th visit to Asia since taking office more than three years ago, reflecting the fierce competition between Washington and Beijing in the region.

He notably arrives two days after the foreign ministers of China and Russia met with those from the 10-nation ASEAN bloc, and each other on the sidelines of the summit.

Wang and Sergei Lavrov had discussed "building a new security architecture for Eurasia", according to Moscow's foreign ministry.

The pair also agreed to jointly "counter any attempts by extra-regional forces to interfere in Southeast Asian affairs", it said.

China has a strong political and economic partnership with Russia, with NATO members labelling Beijing as a "key facilitator" of Moscow's involvement in the war in Ukraine.

Wang and Blinken would "exchange views on issues of common concern", China's foreign ministry spokeswoman Mao Ning said Friday.

Blinken is expected to "discuss the importance of adherence to international law in the South China Sea" at the ASEAN talks, according to the US State Department.

The talks come at a time of high tensions in the South China Sea, where a series of clashes have taken place in recent months between Philippine and Chinese vessels at flashpoint reefs. 

The temperature between Manila and Beijing remains high, despite a deal last week on resupplying Filipino troops stationed on a disputed reef.

Beijing claims the waterway, through which trillions of dollars of trade passes annually, almost in its entirety despite an international court ruling that its assertion has no legal basis.

A Filipino sailor lost a thumb in a June 17 confrontation when Chinese coast guard members wielding knives, sticks and an axe foiled a Philippine Navy attempt to resupply its troops on a remote outpost.

China lashed out earlier this year after Blinken said that Washington was ready to defend the Philippines if its forces, ships or aircraft came under attack in the South China Sea.

Beijing has insisted that the United States has "no right" to interfere in the South China Sea.

The two countries also remain at loggerheads over trade, human rights and the status of the self-ruled island of Taiwan, which China claims sovereignty over.

Blinken is scheduled to travel to Hanoi later Saturday to extend US condolences to Vietnamese officials after the passing of communist leader Nguyen Phu Trong.

The trip will see him visit six countries: Vietnam, Laos, Japan, the Philippines, Singapore and Mongolia.

ASEAN ministers are expected to issue a joint communique at the end of their three-day meeting.

One diplomatic source said the statement is being held up by lack of consensus over the wording of paragraphs on the Myanmar conflict and disputes in the South China Sea.

Myanmar's junta has been banned from high-level ASEAN summits over its 2021 coup and crackdown on dissent but has sent two bureaucrats to represent it at the Laos talks.