US closely watching political crisis in South Korea

A deepening political crisis in South Korea has not diminished the military readiness of 28,500 troops stationed in the Asian state, a U.S. official said on Friday, but Washington is closely monitoring the situation.

South Korea's parliament impeached acting President Han Duck-soo on Friday, less than two weeks after suspending President Yoon Suk Yeol over his short-lived martial law declaration, plunging the country further into political chaos.

Finance Minister Choi Sang-mok assumed the position of acting president while the cases of Yoon and Han are considered by the Constitutional Court.

The United States has troops stationed in South Korea as a legacy of the 1950-1953 Korean War. After the martial law declaration this month, the U.S. and South Korea had postponed a tabletop exercise and U.S. Defense Secretary Lloyd Austin scrapped a trip to South Korea.

A U.S. official, speaking on condition of anonymity, said that while the United States was monitoring the latest developments on Friday, there had been no impact on military readiness on the Korean peninsula.

A State Department spokesperson said South Korea has peacefully followed a process laid out in its constitution, adding Washington is ready to work with Choi and the government.

"We strongly support the ironclad alliance that joins our two countries together and that's done so much over the last few years," the spokesperson said.

The unexpected imposition of martial law and the ensuing political upheaval drew concerns from allies in the U.S. and Europe who had seen Yoon as a partner in efforts to counter China, Russia and North Korea.

U.S. and South Korean officials say more than 10,000 North Korean troops have been deployed to Russia's Kursk region to help push back Ukrainian forces.

A thousand North Korean troops have been killed or wounded in the last week alone in the Kursk region of Russia, the White House said on Friday.