North Korea and the international response to provocations by Pyongyang will be a major focus of White House talks between U.S. President Barack Obama and President Park Geun-hye of South Korea.
The situation on the Korean peninsula may have calmed somewhat in recent weeks, following the height of threats by Pyongyang to attack South Korea and the United States.
The president of South Korea's stops on this visit to the United States.
There have been no new North Korean missile launches, although the U.S., South Korea and other governments in the region are still on alert for any additional provocative acts.
But North Korea's aggressive actions, and the need for ongoing vigilance, are at the top of the agenda in the Oval Office discussions.
Special Assistant to the President and Senior Director for Asian Affairs Daniel Russel says additional provocations cannot be ruled out.
North Korea, he says, should take an important message from the strength of the U.S. - South Korean alliance it has seen over the past month, and that will be on display again Tuesday at the White House.
"The unity of message between the two governments and the two presidents signals to North Korea that it has no hope of gaining benefits from provocation," said Russel. "That we and the world will not try to rent a little peace and quiet by acceding to North Korean demands."
At the same time, says Russel, North Korea could take advantage of a longstanding U.S. offer to engage in discussions if Pyongyang complies with U.N. Security Council resolutions and completes de-nuclearization of the peninsula.
Russel said celebrating any decision by Pyongyang not to undertake further provocations would be premature, adding that Pyongyang needs to do much more.
"[Signs] would need to be credible and irreversible steps signaling a commitment to end their nuclear program and completely de-nuclearize the peninsula," he said.
Russel said President Obama and President Park are in "solid convergence" on a credible deterrence and strong defense, and their determination that North Korea must de-nuclearize.
The international community, he said, would act in response to "meaningful and irreversible steps" toward de-nuclearization, but "not in exchange for promises that historically North Korea has quickly broken."
Tuesday's talks also will focus on bilateral and regional trade issues. Obama and President Park will have a working lunch with officials from both sides, and also will hold a joint news conference.