Myanmar will mark a minute of silence on Tuesday in tribute to victims of the country's devastating earthquake that has killed more than 2,000 people, as hopes dim of finding more survivors in the rubble of ruined buildings.

National flags will fly at half-mast until April 6 "in sympathy for the loss of life and damages" from Friday's massive quake, the ruling junta said in a statement on Monday.

As part of a week of national mourning, the junta announced the minute's silence to begin Tuesday at 12:51:02 pm - the precise time the 7.7-magnitude quake struck.

People should stop where they are to pay respect to the victims, the junta said, while media should halt broadcasting and show mourning symbols, and prayers will be offered at temples and pagodas.

The announcement came as the tempo and urgency of rescue efforts wound down in Mandalay, one of the worst-affected cities and the country's second-largest, with more than 1.7 million inhabitants.

The junta said Monday that 2,056 have now been confirmed dead, with more than 3,900 people injured and 270 still missing, but the toll is expected to rise significantly.

Three Chinese nationals are said to be among the dead, along with two French people.

At least 19 deaths have been confirmed hundreds of kilometres away in Thailand's capital Bangkok, where the force of the quake caused a 30-storey tower block under construction to collapse.

Diggers continue to clear the vast pile of rubble at the site, where a dozen deaths have been confirmed and at least 75 people are still unaccounted for. Officials say they have not given up hope of finding more survivors.

The United States said on Monday it had dispatched a disaster relief team to Myanmar, defending the pace of the deployment following President Donald Trump's dismantling of America's main overseas aid agency.

The earthquake struck on Friday, on the same day that Secretary of State Marco Rubio said he was formally dissolving the US Agency for International Development (USAID), arguing that the "gains were too few and the costs were too high," after cutting more than 80 percent of its projects.

China, Russia and India have already sent teams to Myanmar. (AFP)