US President Joe Biden announced new sanctions on Myanmar’s military leaders on Wednesday, 10 days after a coup in the country.
Mr Biden called on the country's military to step down and release the civilian leaders it is holding.
The promise of sanctions follows the suspension of US aid to the junta.
The move has bipartisan support in Congress, which has been pushing for sanctions since the coup.
Mr Biden said the sanctions would be enacted this week after he signed an executive order on Wednesday allowing for them.
They will include freezing assets, export controls and blocking military leaders’ access to funds in the US, which will also affect their business interests and close family members.
The funds held in the US are estimated at $1 billion, Mr Biden said.
“Today, I again call on the Burmese military to immediately release the democratic political leaders and activists they're now detaining, including Aung San Suu Kyi … and also Win Myint, the President,” he said.
“The military must relinquish the power they’ve seized and demonstrate respect for the will of the people of Burma, as expressed in their November 8 election.”
Mr Biden said the US government held consultations with foreign allies before the announcement, and many of them may also impose sanctions.
He said he had discussions with Congress and Senate minority leader Mitch McConnell, who has publicly pushed for sanctions since the February 1 coup.
“The assault on Burma's transition to democracy remains an issue of deepened bipartisan concern," Mr Biden said.
"We've consulted at length, for example, with McConnell, who has had a very keen interest in this, and his team, and we welcome their helpful insights."
Mr McConnell on Tuesday called for action against Myanmar’s military.
“It’s time to follow up with meaningful costs on those who aid and abet the suffocation of Burmese democracy," he said.
Last week, the US government determined that the events in Myanmar constituted a coup and initiated a cut in US assistance to the junta.
“After a careful review of the facts and circumstances, we have assessed that Aung San Suu Kyi, the leader of Burma's ruling party, and Win Myint, the duly elected head of government, were deposed in a military coup on February 1,” a US senior official said.
US officials have not been able to reach either the country's military chiefs or opposition figures, the Biden administration said.
"A very small circle of Burma's military leaders have chosen their own interests over the will and well-being of the people,” the official said.
Bob Menendez, a Democratic senator from New Jersey who heads the Senate Foreign Relations Committee, welcomed Mr Biden's announcement.
“I look forward to continuing to work with President Biden and Secretary [Antony] Blinken as we return our values to the forefront of our foreign policy and to stand with the people of Burma in the face of military oppression and to assure robust forward-leaning US engagement in the Indo-Pacific.”
Thousands of people have protested in Myanmar this week, defying a security crackdown and social media cut by the military.