SEOUL, South Korea — South Korean President Yoon Suk Yeol apologized on Saturday for declaring martial law but did not say he would resign as he faces an impeachment vote for plunging the key U.S. ally into chaos with his short-lived order.

In a nationally televised address, Yoon said his actions “stemmed from the urgency” he felt as president but “caused anxiety and inconvenience to the public.”

“I deeply regret this and sincerely apologize to the citizens who were alarmed,” he…