North Korea will preserve its nuclear know-how despite its promise of denuclearisation to the United States, Foreign Minister Ri Yong Ho said during a visit to Tehran, Iranian media reported on Thursday.

Despite the agreement to denuclearise the Korean peninsula struck during a landmark summit between North Korean leader Kim Jong-Un and US President Donald Trump, "we preserve our nuclear science as we know that the Americans will not abandon their hostility toward us," Ri said, according to the conservative Mehr news agency.

"Dealing with Americans is difficult, and as our main goal is total disarmament of the whole Korean Peninsula, it is necessary that the Americans also abide by their commitments but they refuse to do so."

At the June summit with Trump, Kim made a vague commitment to denuclearisation — far from the longstanding US demand for the complete, verifiable and irreversible dismantling of Pyongyang's atomic arsenal.

Ri was meeting with Iran's influential parliament speaker Ali Larijani on the third day of an official visit.

"The Americans utter beautiful words when negotiating and promise a very bright future but they deliver on none of their commitments when it comes to action," Larijani said.

Ri arrived in Tehran on the same day as the United States reimposed sanctions after abandoning a 2015 nuclear deal between major powers and Iran.

The other five parties to the deal agree with UN inspectors that Iran has been abiding by its commitments, but Trump has said repeatedly it is "a horrible deal" and announced he was abrogating it in May.

North Korea slams UN chief over call for nuclear disarming
United Nations, United States (AFP) Aug 10, 2018 –

North Korea on Friday accused UN Secretary-General Antonio Guterres of making "reckless remarks" and toeing the US line when he called for verifiable and irreversible denuclearization of the Korean peninsula.

Guterres made the statement following talks with Japanese Prime Minister Shinzo Abe in Tokyo on Wednesday to discuss the US-led effort to rid North Korea of its nuclear and ballistic missile programs.

The UN chief "should do what is beneficial to the current situation on Korean peninsula for peace and stability, not just by singing (the) chorus for sanctions to please (a) certain country," said a statement from the North Korean mission to the United Nations.

The mission described as "reckless" a remark from Guterres who said that North Korea "can be a normal member of the international community in this region through total denuclearization that is verifiable, irreversible."

The statement said North Korea was "astonished" to hear Guterres' remarks "at a time when the world supports and welcomes the historic DPRK-US summit and the joint statement in Singapore."

At the first-ever meeting between sitting leaders of the US and North Korea in June, President Donald Trump and Kim Jong Un pledged in a joint statement to work toward the "complete denuclearization of the Korean Peninsula."

The statement however was short on details and a UN panel of experts reported last week that North Korea is pressing ahead with its nuclear and missile programs.

The United States, backed by Japan, is urging UN member-states to maintain pressure on North Korea to give up its military programs by fully adhering to a raft of sanctions.

Trump's administration has argued that sanctions must remain fully in place until North Korea has scrapped its nuclear and missile programs and that the dismantling is verified.

The Security Council last year adopted three rounds of tough economic sanctions on North Korea, banning most of its exports of raw commodities and severely restricting oil supplies.