"These reprehensible acts of violence further exemplify the regime's complete disregard for human rights and the rule of law," Blinken said in a statement on the executions of a former lawmaker, prominent activist and two others.

"The regime's sham trials and these executions are blatant attempts to extinguish democracy; these actions will never suppress the spirit of the brave people of Burma," Blinken said, using Myanmar's former name.

"The United States joins the people of Burma in their pursuit of freedom and democracy and calls on the regime to respect the democratic aspirations of the people who have shown they do not want to live one more day under the tyranny of military rule."

The United States has unleashed a series of sanctions since Myanmar's military toppled the civilian leadership of Aung San Suu Kyi in February last year, slamming the door on a decade of US-nurtured efforts toward democracy.

Blinken earlier this month met activists from Myanmar in Bangkok and acknowledged that there has been little progress but vowed that the United States would keep up pressure.

State Department spokesman Ned Price told reporters that the United States was discussing new measures and that "all options are on the table" for additional economic pressure.

He called for all nations to unite on Myanmar, saying that the junta's executions were a "direct rebuke" to the Association of Southeast Asian Nations and its current chair Cambodia.

"Arguably no country has the potential to influence the trajectory of Burma's next steps more so than the PRC," Price said of the People's Republic of China.

"There can be no business as usual with this regime. We urge all countries to ban the sale of military equipment to Burma (and) to refrain from lending the regime any degree of international credibility," Price said.

Senator Bob Menendez, chairman of the Senate Foreign Relations Committee, urged President Joe Biden's administration to impose sanctions on Myanmar's state-owned oil and gas company, a measure taken earlier by the European Union.