US Secretary of State Antony Blinken heads to Southeast Asia this week to deepen ties with Washington's strategic allies, an official said Monday, as the United States seeks to bolster its regional stance against an increasingly assertive China.

On a 10-day trip that will see him visit Vietnam, Laos, Japan, the Philippines, Singapore and Mongolia, Blinken will carry a message of US commitment to its allies in the region, said Daniel Kritenbrink, a senior US State Department official.

"We're deepening our bilateral relationships, we're expanding our allied and partner relationships, which have reached unprecedented heights, and we are creating a latticework of mutually reinforcing partnerships together," he said.

The United States has in recent years significantly increased its engagement with several countries in Southeast Asia, particularly those locked in territorial disputes with Beijing in the South China Sea.

Blinken's tour will include his participation in an Association of Southeast Asian Nations (Asean) ministerial meeting in Laos, where he will also meet with his Chinese counterpart Wang Yi on the sidelines.

President Joe Biden has made expanding US alliances in the region a core part of his administration's foreign policy, and Kritenbrink said there was "strong bipartisan support on Capitol Hill for our allies and partners and our approach to the region."

Under Biden, Washington has doubled down on its engagement in what it terms the "Indo-Pacific" region, upgrading ties with several countries in the region and forming the so-called "Quad" alliance, which includes the United States, Japan, Australia and India.

Blinken's visit to Asia will be his 18th to the region since he took office more than three years ago.

"The message that the Secretary is going to be conveying to the region is that America is all in on the Indo-Pacific," said Kritenbrink.

Blinken will begin his six-nation tour in the Vietnamese capital Hanoi, where he will attend the funeral of late communist leader Nguyen Phu Trong which is scheduled to begin tomorrow.

Trong died last week at a military hospital in Hanoi "due to old age and serious illness" at the age of 80.

In Laos, the US Secretary of State will participate on Friday and Saturday in the Asean ministerial meeting, where he will also meet Foreign Minister Wang.

Neither the United States nor China has confirmed whether the meeting will be a full bilateral sit-down or a less formal exchange.