North Korea said Sunday it successfully detonated a hydrogen bomb that can be mounted on an intercontinental ballistic missile in its sixth and most powerful nuclear test.

The confirmation of the test by North Korea came hours after foreign meteorological authorities detected a strong artificial earthquake near its nuclear site in the northeastern area near China.

North Korea said through its official media that the test carried out at noon Pyongyang time was a "perfect success" that proved it now has the ability to adjust the power of a nuclear warhead as it chooses depending on an attack target.

A statement from North Korea's Nuclear Weapons Institute said the test was carried out with a hydrogen bomb of "unprecedentedly big power."

The test is the first since U.S. President Donald Trump took office in January and is a direct challenge to his administration still struggling to come up with measures to rein in North Korea, although it has said all options, including military action, are on the table.

The quake was detected after North Korea said early Sunday morning it has successfully produced a hydrogen bomb compact enough to be loaded on a newly developed ICBM.

(KNS/Kyodo)

The statement read out by a newscaster of the country's official broadcaster in the afternoon said the results of the latest test confirmed the "accuracy and credibility" of the new bomb "to be placed at the payload" of an ICBM.

North Korea last carried out a nuclear test in September last year, the purpose of which, according to the North, was to assess the explosive power of a nuclear warhead designed to be mounted on a ballistic missile.

North Korea is banned by the United Nations from any tests of nuclear or ballistic missile technology and is already subject to tough international sanctions.

But North Korea insists that it has a legitimate right to develop the technologies for self-defense against what it perceives as security threats from the United States and other "hostile" forces.

Japanese officials said the power of the manmade temblor was about 10 times stronger than that from the previous test on Sept. 9 last year, which was a 5.3-magnitude seismic event and coincided with the 68th anniversary of North Korea's founding.

The Japan Meteorological Agency said the latest quake had a magnitude of 6.1.

The China Earthquake Network Center said it detected another quake in North Korea with a magnitude of 4.6 about 8 minutes later, which it described as a "collapse," adding both occurred at a depth of "0 kilometer," a strong indication of artificial phenomena.

North Korea's weapons program seems to be making steady progress marked by the continuation of a series of missile tests this year.

In July, North Korea for the first time test-fired an ICBM that could potentially put many parts of the mainland United States within range.

It also launched an intermediate-range ballistic missile last week that flew over Japan before landing without incident in the northern Pacific Ocean.

Kim has said the launch of the Hwasong-12 missile, which traveled about 2,700 kilometers after crossing over the northern Japanese island of Hokkaido, was a "meaningful prelude to containing Guam," the U.S. Pacific territory that is home to about 7,000 U.S. troops and 160,000 civilians.

On Sunday, prior to the sixth nuclear test, North Korea's official media said Kim inspected the new hydrogen bomb at the institute to learn about its technical specifications and operational characteristics.

Kim was quoted by the state-run Korean Central News Agency as saying the institute should conclude "the final-stage research and development for perfecting the state nuclear force," while also giving it new tasks.

"All components of the H-bomb were homemade," Kim was quoted as saying, adding that North Korea can now produce as many powerful nuclear arms "as it wants."

North Korea's announcement on the bomb with "great destructive power" comes as the United States and its allies seek to put more pressure on North Korea following its flurry of weapons tests.

Also, the test came just hours before Chinese President Xi Jinping was to host a summit of emerging economies, including India and Russia, in the southeastern Chinese city of Xiamen and after Japanese Prime Minister Shinzo Abe and Trump held their third telephone talks since the launch of the intermediate-range missile on Tuesday.

Abe told reporters in Tokyo after the conversation that he and Trump agreed to "increase pressure on North Korea and make it change its policies" by working closely along with South Korea and the rest of the world.

China condemned North Korea for conducting its sixth nuclear test in defiance of repeated warnings from the international community and urged it to avoid taking any "wrong" action.

In Moscow, the Russian Foreign Ministry said that the test showed contempt for U.N. Security Council resolutions and international law and deserved censure to the maximum extent.

But China and Russia have warned that more pressure on North Korea risks further escalating tensions.

Images released by North Korea's official media outlets showed Kim observing a silver, gourd-shaped device purported to be the new hydrogen bomb.

The hydrogen bomb for an ICBM was developed and upgraded based on the results of the North's first hydrogen bomb test on Jan. 6 last year, KCNA said.

(KNS/Kyodo)

It said the hydrogen bomb, the explosive power of which is adjustable from tens to hundreds of kilotons, is a "multi-functional thermonuclear nuke" that can be detonated at high altitudes for "super-powerful electromagnetic pulse" attacks.

After North Korea test-fired an ICBM for the first time, the U.N. Security Council rolled out additional sanctions against Pyongyang aimed at slashing its $3 billion annual export revenue by a third, with measures including a ban on all imports of coal, iron and seafood.

North Korea has reacted sharply to the sanctions and threatened to take countermeasures against the United States and its allies trying to put Pyongyang into a corner.

North Korea has not tamed its ambitions to develop "smaller, lighter and diversified nuclear warheads," although some outside experts still doubt it has mastered the technology to miniaturize them to be deliverable by long-range missiles.