Secretary of State John Kerry Arrives in South Korea Amid Fears of War

TOKYO, April 12, 2013— -- Secretary of State John Kerry arrived in Seoul today on a mission aimed at tempering rising tensions on the Korean peninsula, urging North Korean leader Kim Jong-un to opt for "the peaceful option being offered."

His four day trip to East Asia, which includes stops in China and Japan, came as a wary region braced for a potential missile launch by Pyongyang, for yet another day.

Kerry met with South Korean President Park Geun-Hye, reassuring the new leader the U.S. would defend its ally, and added North Korea's bellicose rhetoric was "simply unacceptable."

In a sign the U.S. was making efforts to tone down its own rhetoric, Kerry stressed the two discussed a "bright vision of possibilities" and the prospect of a reunited Korean peninsula "where the aspirations of two Koreas are being made," he said.

"We want to emphasize that the real goal is not reinforcing that we will defend our allies, but the possibilities of peace, the possibilities of reunification," Kerry said at a joint press conference with South Korean Foreign Minister Yun Byung-se.

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Kerry's visit comes on the heels of an alarming assessment from the Defense Intelligence Agency, expressing "moderate confidence" North Korea might have a nuclear weapon small enough to be placed on a ballistic missile. Sources tell ABC News that sentence, buried deep in a classified report, was accidentally declassified, catching intelligence agencies off guard when Republican Congressman Doug Lamborn asked the Joint Chiefs Chairman about it at a House Armed Services Committee hearing Thursday.

It said the reliability of the missile would be low, but Kerry downplayed the assessment, saying it was inaccurate to suggest the DPRK had demonstrated capabilities to "miniaturize" a nuclear warhead.

"Obviously, they have conducted a nuclear test, so they have some kind of device," he said. "Does it get you to a line that is dangerous? Yes."

For the second straight day, President Park stressed talks with North Korea, saying it was time to listen, to end the vicious cycle of provocation. The sudden shift in tone Thursday raised some eyebrows, with sources close to the presidential office saying they were concerned the "olive branch" was made without consulting the U.S.

But Kerry today expressed support for the president's efforts, saying he would not stand in the way of bilateral talks.

"We have agreed, however, to talk very closely about any steps that any of us will take," he said. "It will be a complete and total process before either of us take any steps."

Kerry heads to China Saturday, where he is expected to pressure Beijing to reign in North Korea, its ally. In recent days, new President Xi Jinping has expressed increasing frustration with Kim Jong-un's erratic behavior, telling delegates at an international forum last weekend, "No one should be allowed to throw a region and even the whole world into chaos for selfish gains," though Xi did not mention North Korea by name.

Kerry said China had "an enormous opportunity" to make a difference, and move talks and negotiations "the right way."

North Korea has repeatedly threatened to attack South Korea, Japan, and U.S. bases on Okinawa and Guam. North Korea issued a fresh round of threats today directed at Japan, for the third time this week.

On a commentary read on state TV, Pyongyang criticized Prime Minister Shinzo Abe's decision to order the interception of North Korea missiles, saying his actions would result in a nuclear attack against the country, according to the Yonhap News Agency. They threatened to make Japan the first target in the event of a war.

Surveillance has shown that Pyongyang is ready to launch its untested mid-range Musudan missile, but Kim has not acted on near daily threats for all out war, so far.

Inside North Korea, the mood has been one of celebration, as the country prepares to mark the 101st birthday of founder Kim Il Sung, the current leader's grandfather, on April 15.

At a flower exhibition featuring massive displays incorporating the orchid named after the late leader, a guide called the current political situation "complicated." Photo backdrops and mock replicas featured a variety of missiles, including models believed to be medium-range and intercontinental ballistic missiles.

Still on high alert, Japan's Defense Ministry confirmed it would deploy two additional PAC-3 patriot missile batteries to Okinawa, where more than half the 47,000 troops based in Japan are stationed. The interceptors were initially scheduled for permanent deployment in 2014, but tensions on the Korean peninsula sped up those plan, according to Kyodo News.

The ministry has already deployed 4 PAC-3s around the Tokyo area, and Aegis destroyers in the Sea of Japan. Earlier this week, the U.S. added the SBX, sea-based radar to its own defenses in the Pacific, allowing the military to track just-launched ballistic missiles.