SEOUL >> North Korean leader Kim Jong Un said Thursday that his country had achieved the “success of all successes” in launching a missile from a submarine, saying it effectively gave the country a fully equipped nuclear attack capability and put the U.S. mainland and bases in the Pacific within striking distance.

Kim’s comments, carried by Pyongyang’s official Korean Central News Agency, came a day after South Korean officials said a ballistic missile fired from a North Korean submarine was tracked flying about 500 kilometers (310 miles), the longest distance achieved by the North for such a weapon.

North Korea already has a variety of land-based missiles that can hit South Korea and Japan, including U.S. military bases in those countries. But its development of reliable submarine-launched missiles would add a weapon that is harder to detect before launch.

The KCNA said Kim watched from an observation post as the test-firing happened, which the agency said was carried out without “any adverse impact” on neighboring countries.

The North’s official Rodong Sinmun newspaper published several photos that showed the missile, with the name Pukguksong printed on its side, soaring into the sky, and Kim smiling and embracing with one of the North Korean officials accompanying him from what appeared to be an observation deck.

The KCNA quoted Kim as saying the successful test showed that North Korea had joined the “front ranks” of military powers fully equipped with nuclear attack capabilities. Kim also said it is undeniable that the U.S. mainland and key operational areas in the Pacific were within North Korea’s striking distance.

“I do not guess what ridiculous remarks the U.S. and its followers will make about this test-fire, but I can say their rash acts will only precipitate their self-destruction,” the KCNA quoted Kim as saying.

The KCNA said the test was aimed at evaluating the stability of the underwater launching system, the flight features of the solid-fuel missile, the reliability of the control and guidance system, and the accuracy of the warhead in hitting targets after it re-enters the atmosphere.

Wednesday’s launch came two days after the U.S. and South Korea began their 12-day Ulchi Freedom Guardian exercises, prompting North Korean threats of retaliation for the military drills, which it views as an invasion rehearsal. North Korea usually responds to regular South Korea-U.S. military drills with weapons tests and fiery warlike rhetoric.

The United Nations Security Council agreed at an emergency meeting late Wednesday requested by the United States and Japan to consider issuing a statement on the missile launch.

Malaysia’s U.N. Ambassador Ramlan Bin Ibrahim, the current council president, told reporters after the closed meeting that “there was a general sense of condemnation by most members of the council.”

He said the United States is drafting the text of a press statement “and we will have a look at it.”

State Department spokeswoman Elizabeth Trudeau said in a statement that the U.S. strongly condemned the launch and called on North Korea to “refrain from actions and rhetoric that further raise tensions in the region.” She said the missile launch marked the latest in an “accelerating campaign” of missile tests that violate multiple U.N. Security Council resolutions.

South Korea’s military condemned the launch but acknowledged it was an improvement over previous tests of similar missiles.

North Korea fired two missiles from submarines earlier this year, but South Korean defense officials believe they exploded in midair after flying less than 18 miles.

The missile, fired from a submarine off the eastern North Korean coastal town of Sinpo, reached into Japan’s air defense identification zone, according to Seoul and Tokyo officials. Its longer distance puts all of South Korea within its range if it is fired near the border.

Missiles of such capability could also potentially strike parts of Japan, including U.S. military bases on the island of Okinawa, considering the operational range of North Korea’s Sinpo-class submarines, said analyst Kim Dong-yub at Seoul’s Institute for Far Eastern Studies.