TEHERAN (AFP) - 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 Teheran, Iranian media reported on Thursday (Aug 9).

Despite the agreement to denuclearise the Korean peninsula, which was struck during a landmark summit between North Korean leader Kim Jong Un and US President Donald Trump in June, "we preserve our nuclear science, as we know that the Americans will not abandon their hostility towards us", Mr 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," he said.

At the summit with Mr Trump, Mr 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.

Mr Ri was meeting 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," Mr Larijani said.

Mr Ri arrived in Teheran on the same day the US reimposed sanctions on Iran after abandoning a 2015 nuclear deal between the country and major powers.

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