The Gulf monarchies and United States accuse Iran of supporting Huthi rebels in Yemen -- and see this as justification for the military campaign they have been waging in Yemen since 2015.

Iran supports the rebels politically but denies supplying them with arms.

The report from UN Secretary General Antonio Guterres' office says his staff examined two container launch units for anti-tank guided missiles recovered by the Saudi-led coalition in Yemen.

"The Secretariat found that they had characteristics of Iranian manufacture," the report said.

"The Secretariat also examined a partly disassembled surface-to-air missile seized by the Saudi-led coalition and observed that its features appeared to be consistent with those of an Iranian missile," it added.

A probe into the origin of the weapons continues, it said.

US Secretary of State Mike Pompeo was expected to attend Wednesday's meeting on Iran, scheduled to start at 1500 GMT.

Guterres' report mainly addresses Iran's obligations under the 2015 nuclear deal it struck with six major powers. The United States pulled out of the accord in May and has reimposed sanctions on Iran.

The report concludes that Iran continues to abide by the nuclear accord, under which it won sanctions relief in exchange for limiting its nuclear program.

The UN has said in the past that Yemen's Huthi rebels have fired Iranian-made missiles at Saudi Arabia. But it said it could not be certain that these weapons were in fact supplied by Iran in what would be a violation of UN resolutions.