WILL NORTH KOREA STRIKE THE SOUTH IN HOURS' TIME?

North Korea kept tensions simmering around its borders.
Thursday, reportedly moving a medium-range missile to its east coast and continuing to put pressure on a joint industrial complex where hundreds of South Koreans work.

Wednesday, the United States announced it was sending ballistic missile defenses to Guam, a Western Pacific territory that's home to U.S. naval and air bases. North Korea has cited those bases among possible targets for missile attacks.

This comes amid the disclosure of what one U.S. official

calls an Obama administration "playbook" of pre-scripted actions and responses to the last several weeks of North Korean rhetoric and provocations.

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 Studies in 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.

North Korea warns 'moment of explosion' nears

A fresh burst of rhetoric

The reported missile activity Thursday followed Pyongyang's latest salvo of ominous rhetoric, which revived the alarming but improbable threat of a nuclear attack against the United States and warned that "the moment of explosion is approaching fast."

The fraught situation on the Korean Peninsula stems from the North's latest long-range rocket launch in December and underground nuclear test in February.

The tougher U.N. sanctions in response to those moves, combined with joint U.S.-South Korean military exercises in the region, have prompted Kim Jong Un's government to ratchet up its threats in recent weeks.

The United States has in turn made a show of its military strength in the annual drills taking place at the moment, flying B-2 stealth bombers capable of carrying conventional or nuclear weapons, Cold War-era B-52s and F-22 Raptor stealth fighters over South Korea.

But those actions have provided fresh material for Pyongyang's rhetorical outbursts, which have portrayed the practice flights as threats against North Korea.

"The moment of explosion is approaching fast. No one can say a war will break out in Korea or not and whether it will break out today or tomorrow," a spokesman for the General Staff of the North's Korean People's Army (KPA) said early Thursday.

"The responsibility for this grave situation entirely rests with the U.S. administration and military warmongers keen to encroach upon the DPRK's sovereignty and bring down its dignified social system with brigandish logic," the KPA spokesman said in a statement published by the state-run Korean Central News Agency (KCNA).

DPRK is short for Democratic People's Republic of Korea, the official name for North Korea.