North Korea said Thursday that no one can deter Pyongyang from bolstering its nuclear force, claiming that the United States' talk of its intent not to seek a regime change in the North is a sheer deceptive scheme.

Rex Tillerson, the top US diplomat, said last week that Washington wants North Korea to trust its promise of no hostility and to not conduct any more nuclear or missile tests before Washington can consider opening talks with the communist nation.

The Korea Asia-Pacific Peace Committee, a side branch agency of the ruling Worker's Party, said that the US is staging a deceptive campaign against the North as it brought about a possible dialogue while sending its strategic assets to the Korean Peninsula.

As long as the US seeks to stifle North Korea, "we will further step up the efforts for diversifying and modernizing the nuclear force before the aggressors and provocateurs come to their senses," a spokesman at the committee was quoted as saying by the Korean Central News Agency.

The warning came as North Korea on Sunday test-fired a ballistic missile, called the Pukguksong-2, threatening that it is ready to deploy the new weapon.

The spokesman also said that South Korea is "dancing to the tune" of outsiders, warning that Seoul should not take issue with North Korea's move to bolster its self-defense.

President Moon Jae-in, a liberal, has vowed to seek a dual-track approach of pushing for North Korea's denuclearization and dialogue with Pyongyang. On Friday, North Korea condemned Moon's policy, saying dialogue can never be compatible with confrontation.

North Korea has long claimed that its development of nuclear weapons is a deterrent against what it calls Washington's hostile policy toward it. (Yonhap)