Questions remain about North Korea's nuclear capabilities and if they will attempt a missile launch soon.
Secretary of State John Kerry arrived in the region today.
He's trying to ease tensions between North and South Korea after the release of a new intelligence report. It concludes that the North could probably equip a long-range missile with a nuclear bomb.
Kerry said people in North Korea are desperate for food, not missile launches.
He reminded the leader of the North, Kim Jong Un, that the U.S. would defend its allies if needed.
"North Korea will not be accepted as a nuclear power," Kerry said.
The Pentagon is trying to downplay a Defense Intelligence Agency report that said, "with moderate confidence the North currently has nuclear weapons capable of delivery by ballistic missiles".
That report was mistakenly declassified.
"General, would you agree with that assessment by DIA?" Rep. Doug Lamborn, R-Colo., asked Gen. Martin E. Dempsey, chairman of the joint chiefs of staff, during a hearing on the defense budget Thursday.
"I'm not going to -- I can't touch that one," Dempsey responded.
Kerry minimized the idea that North Korea was currently ready to use nuclear weapons.
"It is inaccurate to suggest that the DPRK has fully tested, developed, or demonstrated capabilities that are articulated in that report," Kerry said. "Does it get you closer to a line that is more dangerous? Yes."
President Obama made rare remarks about the tension with North Korea. He called on the North to calm down its rhetoric even as the U.S. is moving warships and sophisticated radar into the region in anticipation of a launch.
"Now is the time for North Korea to end the kind of belligerent approach that they've been taking and to try to lower temperatures," the president said.
Secretary Kerry says the U.S. would welcome six-party talks.
That matches one of the biggest developments in South Korea, as President Park indicated she's now willing to talk to the North.
Meanwhile, a spokesman for China's Foreign Ministry says China is willing to work with the U.S. and other members of the six-nation discussions on the nuclear disarmament of the North.
In 2009, Pyongyang walked out of the talks which included South Korea, the U.S., China, Russia and Japan.
Officials in Seoul and Washington say North Korea appears to be preparing to test-fire a medium-range missile designed to reach Guam.