South Korea's defense minister and the military chief are set to meet with the chairman of the US Joint Chiefs of Staff on Monday amid escalating tensions over North Korea's nuclear and missile threats, officials said.

Marine Gen. Joseph Dunford will have separate meetings with Minister Song Young-moo and his South Korean counterpart Lee Sun-jin to discuss responses to North Korea's threats, according to military and government officials.

Dunford arrived in South Korea on Sunday for a two-day visit, the second leg for his tour to Asia which also includes stops in Japan and China.

North Korea's military said last week that it will finalize its plan by mid-August to stage four intermediate-range ballistic missile strikes near the US Pacific island of Guam, home to key American air and naval bases.

Tensions have heightened amid exchanges of incendiary words between Washington and Pyongyang as the North vowed to retaliate against the latest UN sanctions on it spearheaded by the US.

"The minister and the US top military official are expected to discuss ways to counter North Korea's nuclear and missile threats and bolster the Seoul-Washington alliance," Lee Jin-woo, an official at Seoul's defense ministry, told a press briefing.

Dunford is likely to reaffirm Washington's commitment to defend its ally Seoul and offer extended deterrence against North Korea's threats in the event of war, officials said.

Extended deterrence refers to the US commitment to mobilize its full range of conventional and strategic military assets including nuclear capability to protect its allies.

Experts said that North Korea is likely to continue its saber-rattling as Seoul and Washington will conduct their annual joint military drills starting late August. Pyongyang has claimed that the exercise is a rehearsal for an invasion.

North Korea said in June that it can place a moratorium on its nuclear and missile tests if the US suspends the military drills, but Seoul and Washington rejected the idea.

"The government has not considered adjusting the size of the military drill. It is a just and legitimate annual exercise in a defensive nature to counter North Korea's provocations under the allies' defense treaty," said Lee, the ministry official. (Yonhap)