United Nations, Jul 1 (IANS): The Iran nuclear deal remains crucial to regional and international security, said Rosemary DiCarlo, the UN undersecretary-general for political and peacebuilding affairs.

"The Joint Comprehensive Plan of Action (JCPOA), endorsed by (Security Council) Resolution 2231, is a significant achievement of multilateral diplomacy and dialogue. It remains crucial to the global nuclear non-proliferation architecture and to regional and international security," DiCarlo told the Security Council on Tuesday.

It is, therefore, regrettable that the future of this agreement is in doubt after the withdrawal of the US from it and the reversal of some of Iran's commitments, she said.

The US withdrew from the agreement in May 2018.

Before that, the International Atomic Energy Agency (IAEA) verified in 11 reports that Iran was complying with its nuclear commitments contained in the plan, she noted.

"We regret the US withdrawal from the plan. The re-imposition of US national sanctions lifted under the plan, as well as the decision not to extend waivers for the trade in oil with Iran and on all remaining JCPOA-originating projects, are contrary to the goals of the JCPOA.

"These actions have impeded the ability of Iran and other member states to fully implement the plan and the (Security Council) resolution," DiCarlo added.

On March 12 in a letter to UN Secretary-General Antonio Guterres, Iranian Foreign Minister Mohammad Javad Zarif wrote that the US sanctions were constraining his country's response to the COVID-19 pandemic.

Guterres has appealed for the waiving of sanctions that could undermine a country's capacity to respond to the pandemic.

According to DiCarlo, the Secretary-General has expressed concern that the posture of private-sector actors seeking to avert risk may continue to impede legitimate humanitarian aid transactions, especially with regard to banking needs.

The US also regrets the steps Iran has taken since July 2019 in response to the U.S. withdrawal, she said.

As a result of those steps taken under the monitoring of the IAEA, Iran has surpassed JCPOA-stipulated limits on its uranium enrichment level and on its stockpiles of heavy water and low-enriched uranium.

Iran has also lifted JCPOA limitations on its nuclear research and development activities, she said.

"Today, we appeal again to Iran to return to full implementation of the plan. We also urge Iran to address concerns raised by other states regarding its actions inconsistent with the restrictive measures in Annex B of the resolution," DiCarlo said.

Annex B of Resolution 2231 deals mainly with restrictions on Iran's nuclear and ballistic missile programs and on arms transfers.

"We encourage JCPOA participants to resolve all differences within the Dispute Resolution Mechanism under the plan. We also urge all member states to avoid provocative rhetoric and actions that may have a further negative impact on the JCPOA and regional stability," said DiCarlo.