PYONGYANG, September 9. /TASS/. North Korea has officially announced it successfully carried out its fifth nuclear test.

The test confirmed that a nuclear warhead can be mounted on the country’s ballistic rockets, the Nuclear Weapons Institute of the DPRK said in a statement circulated by the Korean Central News Agency on Friday.

"The DPRK will take further measures to bolster the state nuclear force in quality and quantity for safeguarding its dignity and right to existence and genuine peace from the U.S. increasing threat of a nuclear war," the statement said.

The nuclear warhead explosion test is "a demonstration of the toughest will" of the Workers' Party of Korea (WPK) and the Korean people "to get themselves always ready to retaliate against the enemies if they make provocation as it is part of practical countermeasures to the racket of threat and sanctions against the DPRK kicked up by the U.S.-led hostile forces."

The standardization of the nuclear warhead "has definitely put on a higher level the DPRK's technology of mounting nuclear warheads on ballistic rockets," it said.

The Central Committee of the WPK has congratulated nuclear scientists and technicians of the northern nuclear test ground on the successful nuclear warhead explosion test. The institute said the test had "no adverse impact on the ecological environment of the surroundings."

The announcement comes hours after seismologists registered an earthquake in North Korea. The test was conducted on the 68th anniversary of the founding of the Democratic People's Republic of Korea.