Officials said that aides had briefed Mr Biden, who was visiting Angola.
There was speculation in Washington that Mr Yoon might have chosen this moment because the US government is in a transition from the Biden administration to the second Trump one, and because Mr Biden is overseas. Mr Yoon, a first-term president who barely won the 2022 election, has a low approval rating among South Korean citizens, and his move against the opposition party and the legislature has echoes of the effort by Donald Trump to prevent Mr Biden from taking office after he won the 2020 election.
At a US-Japan diplomatic event in Washington, Mr Kurt Campbell, the deputy secretary of state and former Asia adviser to Mr Biden, said that “our alliance with the ROK is ironclad, and we stand by Korea in their time of uncertainty.”
He added that “we have every hope and expectation that any political disputes will be resolved peacefully and in accordance with the rule of law.”
The upheaval is particularly stinging for an American president who has made the promotion of democracy one of his top priorities, in part because of the rise of anti-democratic forces in the United States. Seoul hosted this year’s installment of the global democracy summit that Mr Biden launched several years ago.
At the opening ceremony, Secretary of State Antony Blinken hailed South Korea as a democratic model, saying that it was fitting, “even a little bit poignant,” that the country was hosting the event.
South Korea, Mr Blinken noted proudly, was “a nation that transformed, over a single generation, into one of the strongest, most dynamic democracies in the world, a champion of democracy for the world.”
