In the first official activity since its re-establishment in April, the Foreign Affairs Committee of the Supreme People's Assembly "strongly" condemned the US move and "resolutely” rejected the bill, according to the Korean Central News Agency.

It said in the protest letter that the passage of the bill amounts to the most heinous act against humanity that infringes on North Korea's sovereignty and violates universal principles of non-interference in internal affairs of other countries, it reported.

"The DPRK will keep a watchful eye on the next moves of the US and continue to take legitimate actions for self-defense to counter the hostile policy of the US towards the DPRK," it said.

The DPRK is the acronym for the North's official name -- the Democratic People's Republic of Korea.

North Korea revived the committee after 19 years at its key assembly meeting held on April 11, a move seen aimed at beefing up its diplomacy amid tough international sanctions.

Former North Korean Foreign Minister Ri Su-yong was elected to lead the committee, whose members included Kim Kye-gwan, a vice foreign minister and former top nuclear envoy.

North Korea's diplomatic isolation is deepening as the international community has tightened the screws on Pyongyang over its nuclear and missile program.

The foreign affairs panel was created in 1989 under the late founder Kim Il-sung's regime but was abolished nine years later following a revision of the constitution under his son Kim Jong-il's reign.

Seoul's unification ministry earlier said that North Korea appears to have revived the body to improve its relations with the external world on the basis of its pursuit of nuclear weapons and missiles. (Yonhap)