By David Brunnstrom, Trevor Hunnicutt and Ismail Shakil
WASHINGTON (Reuters) -The United States said on Tuesday it was watching events in ally South Korea with "grave concern" after South Korean President Yoon Suk Yeol declared martial law, and said it hoped the crisis would be resolved peacefully in accordance with the rule of law.
Yoon's surprise declaration, which he cast as aimed at his political foes, created the most serious challenge to South Korea's democracy since the 1980s and was unanimously voted down by 190 lawmakers in the parliament. Protesters gathered outside parliament, and Yoon's own party urged him to lift the decree.
U.S. State Department deputy spokesperson Vedant Patel was asked at a regular news briefing if Washington believed martial law should be rescinded based on the vote.
"Certainly it is our hope and expectation that the laws and regulations of a particular country are abided by that particular country," he said."Ultimately, we want to see these political disputes resolved peacefully and in accordance with the rule of law. And of course, such a vote in the legislature would be consistent with that approach."
Under South Korean law, the president must immediately lift martial law if parliament demands it by a majority vote.
Earlier, U.S. Deputy Secretary of State Kurt Campbell told a State Department event the United States was watching developments in South Korea with "grave concern," and was seeking to engage South Korean counterparts at every level, both in Washington and Seoul.
A White House spokesperson said the U.S. was not notified in advance of Yoon's announcement and added: "We are seriously concerned by the developments we are seeing on the ground."
Campbell said U.S. President Joe Biden, National Security Adviser Jake Sullivan and Secretary of State Antony Blinken were being kept appraised of the situation as it developed. He stressed that the U.S. alliance with South Korea was "ironclad."
"We stand by Korea in their time of uncertainty," he said.
Patel stressed the importance of the "broader strategic partnership" the U.S. has with South Korea and called it "vital partner in the Indo-Pacific."
In Seoul, live television footage showed helmeted troops attempting to enter the National Assembly building. Parliamentary aides were seen trying to push the soldiers back by spraying fire extinguishers.