US Secretary of State John Kerry said on 27 April that the US and its five partners are "closer than ever" to reaching a historic nuclear deal with Iran that would help make people around the world safer.

Kerry told delegates at the a UN meeting on the global nuclear non-proliferation treaty that "the United States and our P5+1 partners have come together with Iran around a series of parameters that if finalised and implemented will close off all Iran's possible pathways to the nuclear material required for a nuclear weapon and give the international community the confidence that it needs to know that Iran's nuclear program is indeed exclusively peaceful.

"I want you to know that the hard work is far from over. And some key issues remain unresolved but we are in fact closer than ever to the good comprehensive deal we are seeking. If we can get there, the entire world will be safer."

Kerry was set to meet with Iranian Foreign Minister Mohammad Javad Zarif on the sidelines of the conference in hopes of progressing toward a long-term atomic deal.

Kerry said the world needs to send a "crystal clear" message to North Korea that it must abandon all nuclear weapons and come into compliance with the IAEA requirements of the non-proliferation treaty.

Kerry said that Washington is working with its regional allies and partners in attempts to renew negotiations, but warned "the onus remains on the DPRK to show that it is actually serious about addressing concerns. Until that happens it will only become more isolated from the rest of the world."