Daryl Kimball, the executive director of the U.S.-based Arms Control Association, made this known to Sputnik on Tuesday.

Earlier this week, a leaked confidential report by a panel of independent UN experts claimed that North Korea had continued its nuclear programme and “probably” managed to develop miniaturised nuclear devices to equip the warheads of its ballistic missiles.

“This means that time is not on our side and it remains urgently necessary to revive the stalled U.S.-DPRK (Democratic People’s Republic of Korea, the formal name of North Korea) talks on denuclearisation and peace.

“This is with the goal of working out a step-for-step programme of action that begins with a verifiable halt of Pyonyang’s production of nuclear bomb material, signature of the Comprehensive Nuclear Test Ban Treaty, and the dismantlement of its main weapons complex at Yongbyon,” Kimball said.

According to the expert, the prospects of rebooting talks currently stumble upon gaps between stances of Washington and Pyongyang, lack of active discussion, “tough talk” and the never-ending threat of sanctions.

“UN Security Council members, including Russia and China, cannot afford to sit on the sidelines and simply complain that others are not doing enough.

“Rather, they should engage directly with Washington and Pyongyang to try to encourage flexibility on both sides so that the situation can be stabilised and the nuclear threats posed by North Korea can be diminished,” Kimball added.

The expert said the report excerpts seemed credible as they reflected what many independent industry specialists knew for quite some time now, namely that North Korea was advancing its nuclear weapons even without ongoing nuclear or long-range ballistic missile tests.

The nuclear programme of North Korea has been subject to concerns of the international community for decades now.

North Korea responded by accusing the IAEA of interference in its domestic affairs and declared its decision to withdraw from the NPT, which was reiterated in 2003.

Three years later, after North Korea’s first nuclear tests, the UN Security Council adopted Resolution S/RES/1695, which condemned the launches and imposed sanctions against Pyongyang.

Since then, a number of resolutions and sanction extensions have been adopted to urge North Korea to abide by non-proliferation and adhere to disarmament, including one urging Pyongyang to adhere to Resolution 1540 on the non-proliferation of weapons of mass destruction.

In 2017, Pyongyang announced that its nuclear programme had achieved the desired result and that the country was ready to launch denuclearisation.

The U.S. and North Korea had two denuclearisation summits in 2018 and 2019, but they eventually faced a deadlock as Washington demanded that Pyongyang completely dismantle all of its nuclear facilities.