North Korean leader Kim Jong Un has warned Pyongyang will not hesitate to launch a nuclear attack if "provoked with nukes."

Kim told his military's missile bureau "not to hesitate (launching) even a nuclear attack when the enemy provokes it with nukes," Pyongyang's official Korean Central News Agency said Thursday.

The warning follows the conduct by the United States, South Korea and Japan of a joint aerial exercise using an American B-1B bomber over waters around the Korean peninsula in a show of force after North Korea's launch of an intercontinental ballistic missile.

The trilateral exercise took place over waters east of the southern resort island of Jeju, where the air defense identification zones of South Korea and Japan overlap, according to Yonhap.

It also follows a meeting between South Korea and the US last week in Washington, where they discussed nuclear deterrence in the event of conflict with the North.

In a separate statement Thursday, Kim's powerful sister, Kim Yo Jong, slammed the United Nations Security Council for convening a session to discuss the North's latest ICBM launch, arguing it was a demonstration of Pyongyang's inherent right to self-defense.

"The ceaseless military drills of the US and its vassal forces (remind) one of the overall preparations for invasion under the pretext of deterring threats from someone," she said, according to KCNA.

"And the frequent appearance of the US nuclear weapons clearly (aimed) at the DPRK … is the root cause of escalating the regional situation," she added, using the acronym for the North's official name.

Washington, Seoul and Tokyo released a statement shortly afterwards, urging the nuclear-armed country to "stop conducting further provocations and accept our call for engaging in substantive dialogue without preconditions."

The three countries have ramped up defense cooperation in the face of a record-breaking series of weapons tests by Pyongyang this year, and on Tuesday activated a system to share real-time data on North Korean missile launches.