UN Secretary-General António Guterres has expressed deep concern over North Korea's new legislation on nuclear policy and its pledge to keep nuclear weapons.

In a Friday briefing, spokesperson for the UN chief Stéphane Dujarric said that increasing the role and significance of nuclear weapons and security doctrines is contrary to decades of efforts made by the international community to reduce and eliminate nuclear risks.

He criticized the North's continued disregard of UN Security Council resolutions, which call for suspending nuclear programs and weapons development. 

North Korea's rubber-stamp parliament has passed a law allowing an "automatic nuclear strike" if the country is attacked. Addressing the parliament Thursday, leader Kim Jong-un stressed the significance of the legislation, saying his country's status as a nuclear power has become irreversible.