Yoon Suk-yeol, presidential candidate of the main opposition People Power Party, looks at the North Korean side with binoculars during his visit to the Baekgol observation post at the South Korean Army’s 3rd Infantry Division in Cheorwon, Gangwon Province. (Yonhap)

President-elect Yoon Suk-yeol was en route to the US military base Camp Humphreys in Pyeongtaek on Thursday, his spokesperson said, as tensions have been running high over North Korea's nuclear and missile programs.

The base, located some 70 kilometers south of Seoul, serves as the headquarters of the 28,500-strong US Forces Korea.

His visit comes as North Korea has ratcheted up tensions by conducting an intercontinental ballistic missile test last month. (Yonhap)