The United Nations says it has determined that Iran was the source for several items in two arms shipments seized by the United States and for debris left by attacks on Saudi Arabia's oil installations and an international airport, according to a new report. UN Secretary-General Antonio Guterres said some of the items seized by the U.S. in November 2019 and February 2020 "were identical or similar" to those found after the cruise missiles and drone attacks on Saudi Arabia in 2019. He said in a report to the UN Security Council obtained on Friday by The Associated Press that some items seized by the US in international waters off Yemen are not only Iranian but may have been transferred "in a manner inconsistent" with the council resolution that endorsed the 2015 Iran nuclear deal. The secretary-general was reporting on implementation of the 2015 resolution enshrining the nuclear agreement aimed at preventing Iran from developing nuclear weapons. It includes restrictions that took effect on January 16, 2016, on transfers to or from Iran of nuclear and ballistic missile material as well as arms. The Security Council is scheduled to discuss the resolution's implementation on June 30, and the US is expected to press for the UN arms embargo against Iran, which is part of it, to be extended indefinitely before it expires in October. Iran's UN Mission responded to the report on Friday saying: "Iran categorically rejects the observations contained in the report concerning the Iranian connection to the export of weapons or their components that are used in attacks on Saudi Arabia and the Iranian origin of alleged US seizures of armaments." Its statement said the UN "lacks the capacity, expertise, and knowledge to conduct such a sophisticated and sensitive investigation," adding that the report reproduces exact claims by the United States. "In essence, the US is sitting in the driver's seat to shape the so-called 'assessment' regarding the Iranian connection to the attacks," Iran said. President Donald Trump withdrew the United States from the nuclear agreement in May 2018 and re-imposed U.S. sanctions that had been eased or lifted. American officials contend Iran is working to obtain nuclear-capable missiles, which the Iranians deny. The nuclear agreement is still supported by the five other parties — France, Britain, Russia and China, which are all veto-wielding Security Council members, and Germany, which is currently serving a two-year term on the council. Mr Guterres cites several exchanges with Tehran rejecting the charges. The report draws on weapons seized by the United States off the coast of Yemen in November 2019 and February of this year which were likely destined for the country's Houthi rebels. Those weapons, or parts of them, were "of Iranian origin," such as anti-tank missiles, or had been "delivered to the Islamic Republic of Iran," such as optical weapons sights, the report said. Items may have been transferred "in a manner inconsistent with resolution 2231" of 2015, the secretary-general said, noting that some of the seized weapons were identical or similar to parts recovered from the 2019 missile and drone attacks. In a letter addressed to Mr Guterres from Iran's UN delegation and dated May 22, Tehran said it had not been policy to export weapons "in violation of relevant arms embargoes of the Security Council." But the letter also insisted that the 2015 resolution "does not prohibit the transfer of arms from Iran." Mr Guterres said UN experts also assessed that sections and components of cruise missiles recovered by the US from the sites of attacks on Saudi Arabia's Abha International Airport in June and August 2019 and on Saudi Aramco oil facilities at Abqaiq and Khurays in September 2019 "are of Iranian origin." As for the delta-wing drones used in attacks on Saudi oil facilities in May and September 2019, Mr Guterres said, "the Secretariat assesses that the un-crewed aerial vehicles and/or parts thereof used in the two attacks are of Iranian origin." The UN's atomic watchdog agency said earlier this month that Iran has continued to increase its stockpiles of enriched uranium above limits in the agreement and remains in violation of its deal with world powers. In his report, Guterres reiterated strong support for the Iranian nuclear agreement and expressed regret for the US withdrawal and Iran's actions since July 2019 to stop performing its nuclear commitments. He urged all countries "to avoid provocative rhetoric and actions that may have a negative impact on regional stability." The secretary-general said the Trump administration's imposition of sanctions on Iran since 2018 remains "contrary to the goals" in the nuclear deal and the UN resolution endorsing it, and may also impede Tehran's ability to implement some provisions of the agreement and the resolution. He urged Iran to return to the agreement's requirements and to "urgently address" concerns raised by the United Kingdom, Germany and France in relation to the 2015 resolution.