U.S. Secretary of State John Kerry arrived in Seoul, South Korea amid increasing bellicose threats from North Korea's leader Kim Jung Un, news reports said.

"If Kim Jung Un decides to launch a missile, whether it's across the Sea of Japan or some other direction, he will be choosing willfully to ignore the entire international community. And it will be a provocation and unwanted act that will raise people's temperatures. It will further isolate his country and further isolate his people who are desperate for food and not missile launches," Secretary of State Kerry warned. "They are desperate for opportunity and not for a leader to flex his muscles."

In the past weeks, North Korea's leader Kim Jung Un has stepped up its threats. A recent intelligence report suggested the reclusive and enigmatic country had the know-how to arm a ballistic missile with a nuclear warhead. Kerry, though, rejected the findings, saying that the country still had not developed or fully tested the nuclear capacities needed for such a step, the AP reported.

He met with South Korean President Park Geun-hye and Foreign Minister, expressing strong words of solidarity, and praising Park's "bright vision" for a prosperous and reunified Korean Peninsula without nuclear weapons. "We will defend our allies. We will stand with South Korea and Japan against these threats. And we will defend ourselves," Kerry said. South Korea's president called for great United Nations action should North Korea make additional provocations.

Some American officials believe that North Korea may have missiles has a range of some 2,500 miles - or enough to reach the U.S. territory of Guam.

Negotiations may still be in the realm of possibility, but ""no one is going to talk for the sake of talking and no one is going to play this round-robin game that gets repeated every few years, which is both unnecessary and dangerous," the U.S. secretary of state reiterated.