(CNN) -- North Korea has fired a missile over Japan which Prime Minister Shinzo Abe called the "most serious and grave" threat to the country.
The missile was fired just before 6 a.m. local time in Japan. The launch set off warnings in the northern part of the country urging people to seek shelter.
It flew over Erimomisaki, on the northern island of Hokkaido, and broke into three pieces before falling into the Pacific Ocean, about 1,180 kilometers off the Japanese coast.
"There is no immediate report of the fallen objects and no damage to the ships and aircraft," Chief Cabinet Secretary Yoshihide Suga said at an emergency press conference.
Speaking to reporters, Abe condemned the launch as a "reckless act."
"We have fully grasped the movement of the missile immediately after their launch and have been taking every possible effort to protect the lives of people," he said.
"It is a serious and grave threat which impairs the safety and peace of the region," Abe said.
He said he was requesting the United Nations Security Council hold an emergency meeting to strengthen pressure on North Korea.
It's the first time North Korea has fired a missile over Japan since 1998, during the testing of a satellite launch vehicle. The only other time is a failed 2009 launch of a missile which landed in the Pacific.
Tuesday's launch comes just three days after Pyongyang test-fired three short-range ballistic missiles from Kangwon province -- of the three, one failed.
It also comes the day after military drills ended between the United States and Japan on Hokkaido.
David Wright, co-director of the Global Security Program at the Union of Concerned Scientists, said the North Koreans had been carefully avoiding Japan for years.
"It is a big deal that they overflew Japan, which they have carefully avoided doing for a number of years, even though it forced them to test missiles on highly lofted trajectories, and forced them to launch their satellites to the south, which is less efficient than launching to the east," he said.
"This will make it more difficult for the US to get Japanese support for diplomacy, unfortunately, at exactly the time when the situation is heating up."
Suga told reporters this launch "could endanger peace and security in the Asia-Pacific region. It is also very dangerous and problematic in terms of the traffic safety of planes and ships."
"The launch is an obvious violation of UN resolutions. We cannot tolerate these repeated provocations by the North. We condemn this in the strongest possible way," he added.
No threat to the US
Earlier, South Korea's Joint Chiefs issued a statement that North Korea "fired an unidentified projectile" from an area near Pyongyang, toward the sea east of the Korean Peninsula, that "flew over Japan."
The Pentagon confirmed a launch had been detected. Spokesman US Army Col. Rob Manning said they were still in the process of assessing it.
Manning said that NORAD determined Tuesday's launch did not pose a threat to North America.
A US official said US spy satellites had been observing preparations for a ballistic missile test that would most likely be an intermediate range missile that could reach Guam. The official says the assessment is ongoing.