DUBAI, United Arab Emirates (AP) — Iran's supreme leader is refusing U.S. assistance to fight the new coronavirus, citing an unfounded conspiracy theory that the virus could be man-made by America.

Ayatollah Ali Khamenei made the comments in a speech in Tehran broadcast live Sunday across Iran marking Nowruz, the Persian New Year. He had called off his usual speech at Imam Reza shrine in Mashhad over the virus outbreak.

He relied on the conspiracy theory to refuse assistance.

“Possibly your (offered) medicine is a way to spread the virus more,” Khamenei said.

His comments come as Iran has over 20,600 confirmed cases of the new coronavirus amid 1,556 reported deaths.

Iran is one of the hardest-hit countries in the world by the new virus. Across the Mideast, Iran represents eight of 10 cases of the virus and those leaving the Islamic Republic have carried the virus to other countries.

Associated Press writer Aya Batrawy in Dubai, United Arab Emirates, contributed to this report.