the International Atomic Energy Agency reported on Tuesday, as the country's six-month conflict with the United States shows no signs of resolution.

IAEA monitors cannot confirm the location or status of Iran's stockpile of uranium enriched to near-weapons-grade levels, according to an 11-page proliferation-restricted document handed over in Vienna.

"The Agency's lack of information about this nuclear material and access to facilities for its verification raises serious proliferation concerns," IAEA Director General Rafael Mariano Grossi wrote in the report. He added that Iran should allow inspectors in "as soon as possible."

The report was published as the United States launched a new wave of strikes against targets in Iran, escalating tensions as the two countries fight for control of the Strait of Hormuz.

The first clashes in about a month occurred on Monday, with neither side willing to concede or commit to resuming peace talks. Oil prices have risen this year due to disruptions in the strait, a key energy transit route.

Grossi reiterated his demands that Iran allow inspectors to resume their work and called for a negotiated settlement to the US-Iran conflict. The agency's Board of Governors will meet next week in Vienna to consider a new resolution condemning Iran.

The number of IAEA inspections in Iran was more than halved last year after the country imposed new restrictions following a 12-day conflict in which Israel and the US attacked its nuclear facilities. Monitors did not return to the damaged facilities at Fordow, Isfahan and Natanz, where 440.9 kilograms of highly enriched uranium and 8,599.6 kilograms of lower enriched material were last detected.