The head of the UN atomic agency has said that the nuclear test is “an extremely regrettable act”.

UN chief Antonio Guterres has condemned the underground nuclear test by North Korea, calling it an act that is “profoundly” destabilising for regional security.

North Korea on Sunday carried out its most powerful nuclear test to date, claiming to have developed an advanced hydrogen bomb that could sit atop an intercontinental ballistic missile.

According to a statement issued by a UN spokesperson, the Secretary-General said that North Korea’s action is yet another serious breach of the its international obligations and undermines international non-proliferation and disarmament efforts.

“This act is also profoundly destabilising for regional security. North Korea is the only country that continues to break the norm against nuclear test explosions,” the statement said, using North Korea’s official name Democratic People’s Republic of Korea.

The UN Chief reiterated his call on North Korean leadership to cease such acts and to comply fully with its international obligations under relevant Security Council resolutions, the statement said, noting that Guterres remains in contact with all parties concerned.

The head of the UN atomic agency has said that the nuclear test is “an extremely regrettable act”.

“This new test, which follows the two tests last year and is the sixth since 2006, is in complete disregard of the repeated demands of the international community,” said Yukiya Amano, Director General of the International Atomic Energy Agency (IAEA), in a statement.

In its resolutions, most recently in 2371, the Security Council has reaffirmed its decisions that North Korea should not conduct any further nuclear tests and should abandon all nuclear weapons and existing nuclear programmes in a complete, verifiable and irreversible manner.