Secretary of State Antony Blinken on Sunday vowed no let-up on pressuring Myanmar's junta, and said China should be in agreement as he met democracy activists on a visit to neighbouring Thailand.

Blinken also met with Thailand's leadership and hailed the kingdom's role in a renewed US push in Southeast Asia, a key area of competition with China.

In a meeting held off-camera to protect family members, the top US diplomat heard from young democracy activists from Myanmar, whose military in February 2021 tossed out the civilian government, slamming the door on a decade-long democratic transition nurtured by Washington.

A group of Myanmar activists in Tokyo hold up placards calling for the release of their ousted leader Aung San Suu Kyi in May 2022
A group of Myanmar activists in Tokyo hold up placards calling for the release of their ousted leader Aung San Suu Kyi in May 2022 AFP / Philip FONG

Blinken acknowledged that the US strategy of sanctions on the junta has not borne fruit but promised that Washington was still focused, even as it puts a priority on combatting Russia's invasion of Ukraine.

"It's unfortunately safe to say that we've seen no positive movement and on the contrary, we continue to see the repression of the Burmese people," Blinken told reporters, using Myanmar's former name of Burma.

"We will continue to look for ways that we can, and other countries can, effectively put pressure on them to move back to the democratic path."

Blinken began a day with Thailand's top brass with talks with Foreign Minister Don Pramudwinai
Blinken began a day with Thailand's top brass with talks with Foreign Minister Don Pramudwinai POOL via AFP / Stefani Reynolds

He called for the Association of Southeast Asian Nations, which in April 2021 reached a "consensus" with the junta that includes dialogue with the opposition, to "hold the regime accountable" over its pledges.

Blinken declined to criticise a recent visit to Myanmar by Chinese Foreign Minister Wang Yi -- with whom the top US diplomat held rare talks Saturday in Bali -- but called on Beijing to support the international calls for democracy.

"I think it's also incumbent upon China and in China's interest to see Burma move back to the path that it was on that it was so violently disrupted from by the coup," Blinken said.

In a visit to Bangkok, Blinken pointed to Thailand's embrace of a new US-led economic plan for Asia as well as its efforts on climate change
In a visit to Bangkok, Blinken pointed to Thailand's embrace of a new US-led economic plan for Asia as well as its efforts on climate change POOL via AFP / Stefani Reynolds

Tens of thousands of people have fled Myanmar, humanitarian conditions have deteriorated and ethnic conflicts have intensified since the military toppled and arrested civilian leader Aung San Suu Kyi.

Blinken heard from young democracy activists from Myanmar, whose military in February 2021 tossed out the civilian government
Blinken heard from young democracy activists from Myanmar, whose military in February 2021 tossed out the civilian government POOL via AFP / Stefani Reynolds

Thailand is America's oldest ally in Asia, famously offering elephants to Abraham Lincoln during the Civil War, but has also increasingly worked with China.

Blinken visited days after a stop by Wang, who has embarked on a more extensive tour of Southeast Asia in which he has highlighted Beijing's lavish infrastructure spending.

Signing an agreement pledging to keep expanding ties, Blinken pointed to Thailand's embrace of a new US-led economic plan for Asia as well as its efforts on climate change.

In Thailand, "we have an ally and partner in the Indo-Pacific of such importance to us in a region that is shaping the trajectory of the 21st century, and it is doing that every single day", Blinken said.

The United States has identified China, with its authoritarian system and burgeoning technological and military resources, as its pre-eminent global rival but both nations have recently sought to lower the temperature, as seen in the unusually long five-hour meeting Saturday between Wang and Blinken.

In Bangkok, Blinken met with Prime Minister Prayut Chan-O-Cha, who called the trip a "happy occasion" and saluted the "close and cordial relations" with the United States.

Blinken's trip marks a continued normalisation of the US relationship with Thailand under Prayut, who led a military coup that ousted the government in 2014, triggering US sanctions.

Prayut became prime minister in 2019 elections, which have ushered in a gradual return to open political discourse.

In a joint statement signed by Blinken and Foreign Minister Don Pramudwinai, the United States and Thailand called democracy "essential" to the two countries' idea of Asia.

"Strong democratic institutions, independent civil society, and free and fair elections are central to this vision, allowing our respective societies to reach their full potential," it said.

Addressing one issue that is a high priority for President Joe Biden's administration, the statement said Washington and Bangkok would promote "open and inclusive societies" for LGBTQ people.

Blinken also praised Thailand for signing up to a Biden plan to connect Southeast Asia with companies that are promoting green energy, saying that firms have already promised $2.7 billion in the country.