Washington has urged the leaders of Myanmar's new military regime to refrain from violence and relinquish power, after the death of a young anti-coup protester sparked new anger against the junta.
Much of the country has been in uproar since troops deposed civilian leader Aung San Suu Kyi on February 1, with large street demonstrations in both urban centres and isolated villages.
Security forces have responded with increasing force, deploying troops against peaceful rallies and firing tear gas, water cannon and rubber bullets.
Condemnation of the violence has been fierce, and US Secretary of State Antony Blinken has held talks with allied countries in recent days to press for a firm international response.
"We reiterate our calls on the Burmese military to refrain from violence against peaceful protesters," spokesman Ned Price told reporters on Friday.
"We will work with partners and allies to press the Burmese military to reverse its actions."
A doctor in Naypyidaw had earlier announced the first confirmed death in the protests.
Mya Thwate Thwate Khaing, who turned 20 last Thursday as she lay unconscious in a hospital bed, was shot in the head during a demonstration in the capital last week.
She has since become a symbol of resistance for protesters, who have hoisted her photos high in demonstrations and even unfurled a massive banner of artwork from a bridge showing the moment she was shot.
"We will regard you as our Martyr," said one social media tribute to the young grocery store worker. "We will bring justice for your loss."
A memorial has since appeared in the streets of Yangon, with residents of the commercial capital laying flowers and messages to the victim.
Her sister Poh Poh told reporters on Friday: "Please all join this protest movement to be more successful. That's all I want to say."
Nearly 550 people have been detained since the coup, according to the Assistance Association for Political Prisoners.
Among those arrested are railway workers, civil servants and bank staff who have walked off their jobs as part of a civil disobedience campaign aimed at crippling the army's ability to govern.
The country emerged from its sixth straight overnight internet curfew on Saturday, a measure imposed as neighbourhoods around the country began setting up watch groups to guard against evening arrests.
Internet monitor Netblocks reported that Wikipedia had been blocked in the country, joining a list of banned content that includes Facebook and other social media services.
A small group of protesters were forcefully dispersed by police and military wielding batons in the northern city of Myitkyina on Friday, according to video posted online and witnesses.
One teacher at the scene said she saw dozens arrested in the scuffle, including two of her colleagues.
"They arrested those who tried to take photos and videos," she told AFP.
The military regime has so far weathered a chorus of international condemnation.
The US, Britain and Canada have all announced sanctions targeting the country's top generals.
The junta has justified its power seizure by alleging widespread electoral fraud in November's elections, which Suu Kyi's party won in a landslide.
The Nobel laureate -- who has not been seen since she was detained in dawn raids -- has been hit with two charges, one of them for possessing unregistered walkie-talkies.
Her hearing is expected on March 1.
This handout satellite image released by Maxar Technologies shows lines of people outside the American Center in Yangon, Myanmar yesterday.