CNN: South Korean Defense Minister Kim Kwan-jin told a parliamentary committee in Seoul that the North has moved a medium-range missile to its east coast for an imminent test firing or military drill. The missile doesn't appear to be aimed at the U.S. mainland, Kim said, according to the semi-official South Korean news agency Yonhap.
The movement of the missile is "of concern, certainly to the U.S. military and to Japan," said Mark Fitzpatrick, director of the Non-Proliferation and Disarmament Program at the International Institute for Strategic Studiesin London.
He said he believed the missile in question was a Musudan, a weapon the North hasn't tested before that is based on a Soviet system with a range of about 2,400 kilometers (1,500 miles), far enough to reach Japan but not Guam.
The U.S. military, which has a string of bases and thousands of troops in Japan, has already moved two warships and a sea-based radar platform closer to the Korean Peninsula to monitor possible missile activity, U.S. defense officials said earlier this week.
"The concerning development is if they test a Musudan and it works, then they have a new proven system that could reach anywhere in Japan," Fitzpatrick said.
Another worry is that the missile's test flight could pass over Japan, straining nerves in an already jittery region.
North Korea isn't believed to have an operational missile that can reach the U.S. mainland at the moment.
The medium-range missile will probably take about two weeks to prepare, Fitzpatrick said, which means a potential launch could coincide with the April 15 anniversary of the the birth of Kim Il Sung, the founder of North Korea and grandfather of its current leader, Kim Jong Un.
Known as "the Day of the Sun," Kim Il Sung's birthday is a major public holiday in North Korea that is usually accompanied by large-scale parades.