The UN nuclear monitoring agency says Iran continues to comply with a landmark 2015 nuclear deal, although its stockpiles of low-enriched uranium and heavy water are growing.
The finding by the International Atomic Energy Agency (IAEA) is included in its latest quarterly report distributed to member states.
In its report on May 31, the agency said the IAEA found Iran had stayed within key limitations spelled out in the agreement, known as the Joint Comprehensive Plan of Action, or JCPOA.
The 2015 deal between Iran and world powers offered Tehran economic incentives -- mainly sanctions relief -- in return for curbing its nuclear program.
However, it has been complicated by Washington's withdrawal last year coupled with reinstated and increased U.S. sanctions.
Earlier this month, Iran announced it would increase its enrichment of uranium beyond levels allowed under the JCPOA if it could not find a way within 60 days to shield itself from U.S. sanctions on its economy and oil industry.
A week ago, Iran said it had increased its capacity to enrich uranium, though only of the lower-enriched uranium allowed under the agreement.
The fresh IAEA quarterly report, however, found Iran continued to comply with the JCPOA and said its inspectors had been given unfettered access to Iranian nuclear facilities.
"Timely and proactive cooperation by Iran in providing such access facilitates implementation of the additional protocol and enhances confidence," the report stated, referring to the procedure detailing safeguards and tools for verification.
According to the IAEA report, Iran's heavy water stockpile rose from 124.8 tons in February to 125.2 tons as of May 26. That’s still below the 130-ton limit.
Its stock of low-enriched uranium was 174.1 kilograms as of May 20, up from 163.8 kilograms in February, the IAEA found. The limit set out by the JCPOA is 202.8 kilograms.
It added that Iran had not enriched any uranium above the level allowed by the JCPOA.
"All centrifuges and associated infrastructure in storage have remained under continuous agency monitoring," the IAEA said.
Trump last year pulled out of the deal which he criticized for neither addressing the Islamic republic's nuclear and missile programs, nor its actions in regional hot spots ranging from the Israeli-Palestinian conflict to the wars in Syria and Yemen.
In recent weeks, tensions have risen in and around the Strait of Hormuz, a key petroleum shipping route at the mouth of the Persian Gulf that Iran has threatened to block.
Earlier this month, Washington announced the deployment of an aircraft carrier battle group and a bomber task force to the Gulf to counter what U.S. officials called "clear indications" of threats from Iran to U.S. interests or its allies in the region.
Amid the deployment, attacks were carried out against oil tankers off the coast of the United Arab Emirates.
The United States and many Arab countries blamed Iran and its proxies for those attacks and others on oil pumping stations in Saudi Arabia.
Tehran has denied any involvement in the incidents.