An official checks a screen at a dealing room in Hana Bank in Seoul, Dec. 9. Yonhap

The Korean currency fell to the lowest level in over two years against the U.S. dollar Monday as a political crisis deepens in Korea in the aftermath of President Yoon Suk Yeol's brief martial law imposition last week.

The Korean won was quoted at 1,437 won per dollar, down 17.8 won from the previous session.

It was the lowest level since Oct. 24, 2022, when the currency traded at 1,439.7 won against the greenback.

The won opened markedly lower at 1,426 won per dollar and dropped to as low as 1,438.25 won at 11:41 a.m.

The Korean won has stayed well below the closely watched level of 1,400 won in recent sessions. It was the worst performer among major peers last week, down 1.86 percent against the dollar.

The stock market also tumbled Monday, with the benchmark Korea Composite Stock Price Index (KOSPI) sinking 2.78 percent to a yearly low of 2,360.58.

The won's weakening came as a political crisis sparked by Yoon's martial law imposition continues to persist following a failed attempt to impeach Yoon.

A motion to impeach Yoon failed Saturday due to the boycott by the ruling People Power Party (PPP), but opposition parties have vowed to file the same motion against Yoon again and again.

PPP leader Han Dong-hoon vowed to seek Yoon's "orderly and early" departure while Prime Minister Han Duck-soo handles state affairs, a plan dismissed by the opposition side as unconstitutional.

Investigations into the incident are under way, with the justice ministry imposing a travel ban on Yoon.

Hundreds of thousands of people held anti-government rallies nationwide over the weekend.

Financial authorities have vowed to mobilize all resources available and take bold steps swiftly, if necessary, against excessive market volatility.

The finance ministry said it also plans to introduce a set of structural measures later in the month to improve foreign exchange liquidity and inflows. (Yonhap)