There isn’t really a “martial law” in the United States, but there are ways to limit civil liberties, constitutional experts say.

Though martial law isn't well defined in U.S. law, it has been imposed at the state and federal level to respond to emergencies.

The United States was not aware of South Korean President Yoon Suk Yeol's intention to declare martial law, U.S. Secretary State Antony Blinken told Reuters on Wednesday, adding that he was anticipating speaking with his South Korean counterpart in the coming days.