US Secretary of State John Kerry arrived today in South Korea as Seoul called for talks to ease tensions in the Korean Peninsula amid growing concerns over North Korea’s capability to launch nuclear-armed missiles.

Kerry was to meet with South Korean President Park Geun Hye and Foreign Minister Yun Byung Se during his first visit as US Secretary of State in Seoul.

The meetings were expected to focus on Pyongyang’s threats against Seoul and its formal ally the United States, foreign ministry officials said.

Seoul said it was open to holding talks with Pyongyang to calm the tensions which have been escalating since North Korea’s third nuclear test in February.

Park told ruling party lawmakers late on Thursday that she intends to initiate a dialogue with North Korea, Ministry of Unification spokesman Kim Hyung Suk said.

Park’s comments “can be translated as a message that says South Korea wants dialogue and that the North should do the same,” Kim told reporters on Friday.

Officials in Seoul and Washington played down fears of a strike by the reclusive regime following a US intelligence report that concluded with “moderate confidence” that Pyongyang has learned to make nuclear weapons small enough to be mounted on ballistic missiles.

“North Korea has conducted three nuclear tests, but it is still doubtful that North Korea has made a small, light warhead that can be mounted on a missile,” Defence Ministry spokesman Kim Min Seok said in a press briefing.

The Pentagon also denied the assessment made by the Defence Intelligence Agency, which was revealed by US Congressman Dough Lamborn on Thursday.

“It would be inaccurate to suggest that the North Korean regime has fully tested, developed, or demonstrated the kinds of nuclear capabilities referenced in the passage,” spokesman George Little said Thursday.

US’ commitment to broader cooperation in Asia

The US Department of State said Kerry’s visit to Asia, which was to include stops in Japan and China, aims to re-affirm the US commitment to broader security and economic cooperation in Asia.

US President Barack Obama on Thursday vowed that Washington would continue to resolve the Korean conflict diplomatically, but stressed it would take “all necessary steps” to protect itself and its allies in the region.

“Nobody wants to see a conflict on the Korean peninsula,” he told reporters after meeting with UN Secretary General Ban Ki-moon.

“But it’s important for North Korea, like every other country in the world, to observe the basic rules and norms that are set forth, including a wide variety of UN resolutions,” he added.

Ban also urged Pyongyang’s leader, Kim Jong Un, to refrain from taking more provocative actions and instead work on improving the lives of North Koreans.

“He should refrain from making any further provocation and to do more to enhance the living standard, as well as for eventual peace and reunification of the Korean Peninsula,” he said in a message in Korean to the North Korean leader on CNN.

“I have made it consistently clear that I am ready to visit (North Korea) when and if my visit is helpful and in close coordination with the concerned parties, particularly (South Korea) and the United States,” he added.