A South Korean employee at a US military base in Pyeongtaek, some 70 kilometers south of Seoul, has tested positive for the new coronavirus, US Forces Korea (USFK) has said.

The contractor who works at Camp Humprheys was confirmed to have contracted COVID-19 on Friday after developing symptoms, according to the USFK. He lasted visited the base Wednesday.

The contractor was in isolation at his off-installation home, waiting to be transferred to a medical facility designated for virus patients, the US military said Sunday.

"KDCA and USFK health professionals are actively conducting contact tracing to determine whether anyone else may have been exposed, and to identify and ensure all known on-post and off-post facilities visited by the contractor are thoroughly cleaned," it said in a release. KDCA stands for the Korea Disease Control and Prevention Agency.

The total number of coronavirus cases among the USFK-affiliated population rose to 443, most of whom have tested positive upon arrival in South Korea from the United States.

Amid a resurgence of infections in South Korea, USFK raised its health protection level for all areas in the country to the third-highest level of Charlie in its five-tier system Saturday. (Yonhap)