South Korea is considering all measures to defuse tensions with North Korea and will leave the door open for dialogue, the country's vice unification minister said Sunday.

Chun Hae-sung made the remark as tensions between the North and the United States heightened amid Pyongyang's threat to stage four missile strikes toward the US Pacific Island of Guam.

"The government is considering all necessary steps to reduce tensions on the peninsula and keep peace based on the strong alliance between Seoul and Washington, and cooperation with partners," Chun said during his congratulatory message for a chorus event on unification.

"At the same time, South Korea, a key stakeholder to issues on the Korean Peninsula, will leave the door open for dialogue with the North and make various efforts to fundamentally resolve tensions," he added.

Pyongyang and Washington have traded belligerent rhetoric after the North vowed to retaliate against the new UN sanctions spearheaded by the US to punish the regime's intercontinental ballistic missile tests in July.

The escalating tensions overshadowed Seoul's move to seek engagement with the North. South Korea earlier proposed inter-Korean military and separated family reunion talks with the North, but the North has kept mum toward the offer.

"The government will persistently seek to restore the stalled inter-Korean talks and cooperation to resolve North Korea's nuclear issue and improve ties between the two Koreas," Chun said. (Yonhap)