North Korea launched a new long-range ballistic missile that flew over northeast Japan on Monday and into the Pacific ocean, according to the U.S. military in Japan.

Attributing data from U.S. Forces in Japan, the Defense Agency said the new missile, a two-stage type, was launched from North Korea's east coast at around 12:12 p.m., flew over the Sea of Japan and unspecified Japanese territory, and landed in the Pacific ocean about 500-600 km off the Sanriku coast of Japan's Tohoku region.

The top government spokesman, Chief Cabinet Secretary Hiromu Nonaka, said the missile launch, currently believed to have been a test, would "seriously impact the situation in Northeast Asia." Nonaka also condemned the lack of advance notice as extremely dangerous because of fishing boats that were under the flight trajectory of the missile's first stage, which is believed to have landed about 300 km southeast of Vladivostok, Russia.

But the launch did not come unexpectedly. Japan had been trying to persuade Pyongyang through various channels not to hold the test, after receiving a tip from the U.S. in mid-August that a launch appeared imminent. Although Japan has no diplomatic relations with North Korea, it has issued a strong complaint through its embassy in Beijing, China.

Monday's test -- the first ballistic missile firing by the north since the launch of a missile that is widely believed to have been a Rodong-1, into the Sea of Japan in May 1993 -- immediately sparked speculation that Monday's missile was the same type. However, the South Korean Defense Ministry believes it was a different missile that has a range of 2,000 km -- twice that of the Rodong-1 -- called the Taepodong-1.