South Korea reassured the United States on Thursday amid claims North Korea’s recent dialogue overture was aimed at driving a wedge between the allies.

During a meeting with Washington’s key representatives on the peninsula, South Korean Foreign Minister Kang Kyung-wha insisted they must “stay closely in touch”.

Any dialogue with Pyongyang “cannot go separately from our joint endeavors to deal with North Korea's nuclear and missile threats,” Kang told U.S. Ambassador Marc Knapper and U.S. Forces Korea commander Gen. Vincent K. Brooks, according to local news agency Yonhap.

Thursday also saw the Koreas make contact via a hotline at their tense border for a second consecutive day, although the South is yet to pin down a date for high-level talks. The Panmunjom communication channel was reopened after a 23-month suspension on Wednesday following North Korean leader Kim Jong-un’s New Year’s Day address calling for Seoul-Pyongyang dialogue.

While South Korea is keen to ensure a peaceful Winter Olympics and Paralympics in PyeongChang from next month, the North remains hostile to the U.S. -- threatening again this week to launch a nuclear attack on the American mainland if necessary.

But the South’s military is playing down American media reports, suggesting a first North Korean ICBM (intercontinental ballistic missile) test of 2018 could be imminent.

South Korean President Moon Jae-in proposed to the U.S. last month that joint military drills be delayed until after the Paralympics in March as long as the North refrains from provocations.

“There is no activity that would lead to an assessment that a missile provocation by North Korea is imminent," the South’s Joint Chiefs of Staff spokesman Army Col. Roh Jae-cheon told reporters at a briefing Thursday.