North Korean leader Kim Jong Un has pledged to increase his nuclear arsenal in the new year to stifle U.S. and South Korean hostile acts, in a policy-setting address in which he left almost no opening for a return to long-stalled disarmament talks.

In a speech that came at the end of a nearly weeklong meeting of his ruling Workers Party, Kim said Washington and Seoul are taking aim at his government, which raises his need to produce even more nuclear weapons, the state-run Korean Central News Agency reported on Sunday.

"Now that the south Korean puppet forces who designated the DPRK as their ‘principal army’ and openly trumpet about ‘preparations for war’ have assumed our undoubted enemy, it highlights the importance and necessity of a mass-producing of tactical nuclear weapons and calls for an exponential increase of the country’s nuclear arsenal,” KCNA cited Kim as saying in a report, referring to his country's official name, the Democratic People’s Republic of Korea.