Yoon made the announcement during a televised briefing, vowing to “eradicate pro-North Korean forces and protect the constitutional democratic order”.
It wasn’t immediately clear how the steps would affect the country’s governance and democracy.
Yoon — whose approval rating has dipped in recent months — has struggled to push his agenda against an opposition-controlled parliament since taking office in 2022.
Yoon’s conservative People Power Party had been locked in an impasse with the liberal opposition Democratic Party over next year’s budget bill.
He has also been dismissing calls for independent investigations into scandals involving his wife and top officials, drawing quick, strong rebukes from his political rivals.
The Democratic Party reportedly called an emergency meeting of its lawmakers following Yoon’s announcement.
