The UN nuclear watchdog said Wednesday that North Korea’s test of a hydrogen bomb, if confirmed, is a violation of UN Security Council resolutions and is “deeply regrettable”.

North Korea’s test, “if confirmed, is in clear violation of UN Security Council resolutions and is deeply regrettable,” said International Atomic Energy Agency chief Yukiya Amano.

“I strongly urge the DPRK (North Korea) to implement fully all relevant resolutions of the UN Security Council and the IAEA,” he said in a statement.

The IAEA has not had access to North Korea since being expelled in 2009 but Amano said the Vienna-based body remains ready to resume inspections “once a political agreement is reached among countries concerned.”