PHNOM PENH (AFP) - Asean ministers will push to ramp up pressure on Myanmar's junta at a regional meeting on Wednesday (Aug 3) in Cambodia as the US House Speaker Nancy Pelosi's visit to Taiwan threatens to overshadow proceedings with tensions between Washington and Beijing soaring.

The 10-country Association of Southeast Asian Nations (Asean) - which has spearheaded so far fruitless efforts to restore peace - last week condemned the military's execution of four prisoners, with parts of the bloc growing frustrated at the lack of progress.

A coup in Myanmar last year left the country in chaos with the death toll from a brutal military crackdown on dissent passing 2,100, according to a local monitoring group, and human rights groups urging concrete action.

But Mrs Pelosi's visit threatens to eclipse Myanmar discussions, with attention instead focused on Chinese Foreign Minister Wang Yi and his American counterpart Antony Blinken - both flying into the Cambodian capital.

Late Tuesday China vowed there would be "targeted military actions" in response to her visiting the self-ruled island Beijing claims as part of its territory.

Meanwhile, Asean foreign ministers - meeting face-to-face for the first time since the pandemic - are expected to lament the lack of progress on the regional bloc's "five-point consensus" plan on Myanmar's conflict.

Agreed to in April last year, the plan called for an immediate end to violence and dialogue between the junta and coup opponents.

But after more than a year of no progress on the plan, Malaysia has said it would present a framework for its implementation, even as critics deride Asean as a toothless talking shop.

"Peace can wait, but saving lives can not wait," said Cambodia's Asean spokesman Kung Phoak, while speaking up gains in humanitarian aid delivery.

The absence of Myanmar's top diplomat, Wunna Maung Lwin, or any representative from the country however may stymie progress, he admitted.

South China Sea

The ongoing South China Sea tensions will be another hot-button issue on the agenda.

Beijing claims most of the sea - with competing territorial assertions from Brunei, Malaysia, the Philippines, Taiwan and Vietnam.

Cambodia - a key Beijing ally - last hosted Asean in 2012 and was accused of siding with China over the disputed and resource-rich waters, resulting in no communique being issued.

But based on the progress of a senior officials' meeting, Kung Phoak said he was confident a consensus could be reached and a joint statement released.

"I'm confident things are moving in the right direction. We're almost there," he said on Tuesday.

Alongside Mr Blinken and Mr Wang, Russia's top diplomat Sergei Lavrov - who will make a stop in Myanmar for talks with the junta before travelling on to Cambodia - and the European Union's Josep Borrell will attend meetings with Asean counterparts later in the week.

Ministers are expected to grapple with issues ranging from the Russian-Ukraine conflict to North Korea missile tests and regional security concerns.