From CNN:

Under the country's constitution, the president has the power to declare extraordinary martial law, which allows special measures influencing freedoms of speech, press, assembly and association.

The president must then notify the National Assembly of his decision — but if a majority of lawmakers vote to lift martial law, "the president shall comply," according to the constitution.

The president's cabinet must then "deliberate" and review the decision to lift martial law, according to the constitution.

It's not clear whether Yoon will comply with the lawmakers' vote as required by law, or what the cabinet will say.

Even the leader of Yoon's ruling People Power Party, Han Dong-hoon, called on the president to lift the decree, according to news agency Yonhap.

Yejin Gim, a South Korean journalist based in NYC, shares what is happening and the details of the process under South Korean law.

Per CNN:

Yoon did not say what specific measures would be taken. He cited a motion by the opposition Democratic Party, which has a majority in parliament, to impeach top prosecutors and reject a government budget proposal.

Yoon labeled the opposition's actions as "clear anti-state behavior aimed at inciting rebellion." He further claimed these acts have "paralyzed state affairs and turned the National Assembly into a den of criminals."

He describing martial law as a necessary measure to eradicate these "shameless pro-North anti-state forces." He justified the decision as essential to protect the freedoms and safety of the people, ensure the country's sustainability, and pass on a stable nation to future generations.

The parliament speaker is traveling to parliament and plans to convene a session, according to local broadcaster YTN TV. Yonhap news agency reported though that the entrance to parliament is blocked and lawmakers are unable to enter.