Iran said Monday it could produce higher enriched uranium within two days if the United States quits a 2015 nuclear deal between Tehran and six major powers, Tehran's Arabic language al-Alam TV reported.

"If America pulls out of the deal ... Iran could resume its 20 percent uranium enrichment in less than 48 hours," Behrouz Kamalvandi, spokesman for the Atomic Energy Organisation of Iran, told al-Alam TV.

Uranium refined to 20 percent fissile purity is well beyond the 5 percent normally required to fuel civilian nuclear power plants, though still well short of highly enriched, or 80-90 percent, purity needed for a nuclear bomb.

Kamalvandi said the deal - under which Iran curbed its uranium enrichment to help ensure it was for peaceful purposes only and secured an end to financial sanctions in return - is not re-negotiable, as demanded by the United States. The deal's European signatories - Germany, Britain and France, as well as Russia and China - are committed to preserving the agreement.