US Secretary of State John Kerry stressed that he will not accept a nuclear-armed North Korean state, and that the US is "fully committed" to defending its ally South Korea. Giving remarks after his meeting with Korean Foreign Minister Yun Byung-se, Kerry said their primary focus was the North Korean threat. "Together, we call upon Pyongyang to start down the path of fulfilling its international obligation and commitments," he stated. "And most importantly, we call on the Republic - on North Korea to denuclearize." "We will not accept North Korea as a nuclear state nor as a nuclear-armed state, and nor will the international community abide by that," he added. Kerry said US support for South Korea includes "extended deterrents and putting the full range of US military capabilities in place." "We will continue to modernize our capabilities so that we are prepared to face any threat," he noted. For his part, Yun said that engaging with China is crucial to approaching North Korea's nuclear issue. "In this regard, we agreed to place this issue at the top of our agenda so that we can better cope with the increasing volatility of the nuclear issue arising from the evolving political situation in North Korea." Yun is the first foreign official to visit the US Department of State in 2014.