MOSCOW, May 14. /TASS/. North Korea test-launched a missile of an unknown type early on Sunday, South Korea’s Yonhap news agency reported citing the country’s military.

"The North launched the missile from the country's northwest city of Kusong," the South Korean agency reported, citing the Joint Chief of Staff.

The projectile is "believed to be ballistic missile", the agency said without giving no further details such as the distance it flew or the time of the launch.

According to Japan’s Kyodo news agency, which cited an unnamed Japanese government source, Pyongyang could be testing a new type of a ballistic missile. The assumption is based on the fact that the projectile’s trajectory was very steep and similar to space launches.

"The missile reached an altitude higher than 1,000 kilometers during its flight, raising the possibility that it was launched at a steep "lofted" trajectory. Deliberately firing the missile at such an angle could allow North Korea to test its capabilities without it landing closer to Japan," the agency reported.

According to South Korean military sources, quoted by Kyodo, the ballistic missile covered about 700 kilometers before splashing down in the Sea of Japan.

The Hawaii-based US Pacific Command said it had detected and assessed the missile launch, and came to a conclusion that "the flight was not consistent with an intercontinental ballistic missile," spokesman Rob Shuford said in a statement.

Japanese Chief Cabinet Secretary Yoshihide Suga said the missile was launched at about 5:28 a.m. local time and flew for some 30 minutes. No damage to vessels in the zone of the splashdown has been reported to date,

"The missile was launched from the Kusong city area. It covered about 800 kilometers and landed in the Sea of Japan, some 400 kilometers away from the country’s territory, outside the exclusive economic zone," he told reporters.

Japanese Prime Minister Shinzo Abe described the move as "absolutely unacceptable," adding that his country would continue to work with its allies in the United States and South Korea to ensure the safety of its people, Kyodo reported.

"These repeated missile launches by North Korea are a grave threat to our country and are in clear violation of U.N. Security Council resolutions," Abe said.

Tensions on the Korean Peninsula began to grow in early 2016 when North Korea conducted a nuclear test and after that launched a ballistic missile carrying a satellite. In September 2016, Pyongyang carried out another nuclear test, while more than 20 missiles were test-fired during the year.

In April 2017, North Korea carried out several missile tests the latest of which took place on April 29, only a few hours after the United Nations Security Council had held a meeting to discuss the situation on the Korean Peninsula. The most recent test of a ballistic missile took place in February. The missile covered 700 kilometers and landed in the Sea of Japan.

Meanwhile, in early March, the media reported that North Korea was making preparations for the sixth nuclear test.