Officials work at a dealing room in Hana Bank, Seoul, Thursday. Yonhap

Korean stocks opened sharply lower Thursday, tracking overnight losses on Wall Street caused by uncertainty over negotiations between the United States and Iran to end their war in the Middle East.

After starting 2.02 percent lower, the benchmark Korea Composite Stock Price Index (KOSPI) lost 180.03 points, or 2.05 percent, to 8,621.46 as of 9:15 a.m.

The KOSPI closed at an all-time high of 8,801.49 on Tuesday. The local stock market was closed Wednesday for the election.

Overnight, U.S. stocks ended lower amid concerns that an escalation of hostilities between the U.S. and Iran could undermine prospects for a peace agreement.