S Korea's next leader faces escalating N Korean nuke threat

Yoon Suk Yeol takes office as South Korea's president Tuesday amid heightened animosities over North Korea's nuclear program

SEOUL, South Korea -- During his election campaign, South Korean President-elect Yoon Suk Yeol had tough words for North Korean leader Kim Jong Un, saying he would teach his rival some manners and sternly deal with his provocative missile tests with a strengthened alliance with the United States.

But as he takes office Tuesday for a single five-year term, the conservative Yoon must now confront an increasingly belligerent Kim, who openly threatens to use atomic bombs and is reportedly preparing for his first nuclear test explosion in four years, part of an effort to build warheads that specifically target South Korea.

North Korea has a history of trying to rattle new governments in Seoul and Washington to gain leverage in future negotiations. But if Kim orders a nuclear test, Yoon would be left with very limited options to deal with Kim at the start of his presidency.

There's skepticism among experts over whether Yoon, despite his rhetoric, can accomplish something meaningfully different from outgoing President Moon Jae-in while North Korea continues to reject talks and focuses instead on expanding its nuclear and missile programs despite limited resources and economic difficulties.