In an exclusive interview with the Shargh newspaper published on Wednesday, Ban also said if the agreement with Iran falls apart, it will be much more difficult for the U.S. to reach an agreement with North Korea.

The following is the text of the interview:

Q: How do you see the current situation surrounding the JCPOA? Is it working or collapsing?

A: I am worried by the threats to the JCPOA, and to the international nuclear arms control architecture more widely. Multilateral agreements that have taken years of work to put together are being rapidly ripped up, making the world a more dangerous place.

It was a grave error for the U.S. to walk away from the JCPOA. I have spoken about this many times, and so have The Elders, the group of independent global leaders that I am part of. The JCPOA is an achievement of multilateral diplomacy, and it was working until the U.S. withdrew unilaterally. We should all remember that the JCPOA is not just a multilateral agreement; as it was formally approved by the UN Security Council in a resolution – agreed by the United States government and all other members – it is actually part of international law.

Q: How do you see the European efforts to save the deal and Iran’s actions regarding the agreement?

A: The world’s nuclear watchdog, the International Atomic Energy Agency (IAEA), was able to confirm repeatedly that Iran was abiding by all of its commitments under the JCPOA, until very recently – when Iran decided that it would increase uranium production beyond those limits, in response to U.S. sanctions and the failure of other signatories to live up to their obligations under the agreement. I have taken careful note that Iranian officials have repeatedly said they want to remain within the framework of the agreement and that this decision on uranium enrichment is reversible.

I hope that it will be reversed and that the agreement can be kept alive. All of the signatories other than the U.S. remain committed to the agreement, and want to continue to engage with Iran diplomatically and economically. Iran is known as a country with a proud history; it has made an enormous contribution to the cultural and scientific heritage of the world. Everyone in a position to contribute should work for it to have strong, positive relations of mutual respect with the whole of the international community.

Q: How do the prospects of the JCPOA, and in general, the prospects of Iran’s relations with the West look like to you?

A: The JCPOA dealt only with nuclear issues, not with the other political or security disputes between Western countries and Iran, nor between Iran and its regional neighbors. But many hoped that the JCPOA could be a starting point for a much wider process of re-engagement between Iran and other countries. It is vital that the current U.S. administration’s policies towards Iran do not stop the rest of the world from realizing their hopes of working more constructively with Iran.

Beyond Iran itself, the threats to the JCPOA are bad news for non-proliferation efforts around the world. If the agreement with Iran falls apart, it will be much more difficult for the U.S. to reach an agreement with North Korea on its own, [with a] much more advanced nuclear program. The inconsistency on display damages U.S. credibility and undermines international law.