
North Korea raised concern in late April when it explicitly threatened to test-fire an intercontinental ballistic missile and warned of a nuclear test. The regime followed through with the atomic blast in May, leaving the ICBM test as its next likely step.
"I totally expect that we will see another long-range missile launch ... because they said they will do it," Ralph Cossa, president of the Pacific Forum CSIS think tank, told The Associated Press from Beijing where he was attending a nonproliferation conference.
The North's April launch, which is estimated to have sent a rocket about 2,000 miles (3,200 kilometers), represented a "significant advance" in the country's long-range rocket technology, the Bulletin of Atomic Scientists said in a recent report.
South Korea believes the Taepodong 2 can travel at least 4,100 miles (6,700 kilometers), putting Alaska and Guam within striking distance. The North is also believed to be developing an advanced version of the Taepodong 2 that could reach not only Hawaii, but also the West Coast of the U.S. with a potential range of about 5,000 miles (8,000 kilometers).
Pyongyang had earlier marked a large area of water off its east coast as a no-sail zone through July 10, citing military drills. Thursday's launches of four short-range missiles were believed to be the North's first military action in the designated zone.
Yonhap news agency, citing an unnamed military official, reported that all four missiles flew about 60 miles (100 kilometers) and identified them as KN-01 missiles with a range of up to 100 miles (160 kilometers).
Japanese Prime Minister Taro Aso denounced the launches as "provocative." South Korea's foreign minister, Yu Myung-hwan, said the firings are "not a good sign because they are demonstrating their military power."
South Korean analysts were skeptical about the possibility of a long-range launch anytime soon.
Koh Yu-hwan, a professor at Seoul's Dongguk University, said he expects the North will take more time to assess international reaction to its recent pledge to expand its nuclear program.