U.S. officials believe North Korea has removed two mid-range missiles from imminent-launch status, in an apparent further easing of tensions on the Korean peninsula.
Speaking anonymously late Monday, Washington defense officials said Pyongyang recently moved the two Musudan missiles from a launch site on the country's east coast. South Korean media are also reporting the move.
Washington had for weeks warned North Korea could launch the untested Musudan missiles, which have a range of up to 3,500 kilometers and could reach several U.S. targets in the region.
Daniel Russel, the White House Senior Director for Asian Affairs, says it is premature to celebrate the move as "good news," warning that U.S. officials cannot rule out a test.
North Korea has gradually reduced the intensity of its rhetoric, following weeks of threats of nuclear and conventional attacks against the U.S. and South Korea.
It also comes just before South Korean President Park Geun-hye meets Tuesday in Washington with U.S. President Barack Obama, for talks likely to focus on Pyongyang.
Park began her five-day visit to the United States at the United Nations on Monday. U.N. Secretary-General Ban Ki-moon praised the South Korean president for what he called her "firm, but measured" response to provocations by North Korea.
At a dinner event for Korean Americans held in Washington Monday night, President Park said her government is responding to North Korean threats in a "firm and calm manner" by coordinating with the international community, including both the United States and China. She said South Korea is open to establishing a cooperative relationship with its northern neighbor.
"If North Korea stops its provocations and moves toward a right path embraced by the international community, even at this moment we will open the way for the prosperity of the two Koreas through an inter-Korean trust building process," she said.
The South Korean leader is also scheduled to address a joint meeting of Congress on Wednesday. President Park, who is heading a delegation of more than 50 South Korean business leaders, will stop in Los Angeles Thursday to meet with Korean entrepreneurs.
White House officials say the trip is meant to reaffirm the U.S. commitment of the defense of South Korea.
Pyongyang has been upset at United Nations sanctions that were expanded in response to its latest nuclear test. It also responded angrily to annual joint military exercises between the U.S. and South Korea.
Slide show on North Korea