WASHINGTON: A bill was introduced in the US House of Representatives on Thursday aimed at tightening the terms of the Iran nuclear deal, despite Tehran's rejection of changes to the accord.

US President Donald Trump has repeatedly criticized the agreement aimed at curbing Tehran's nuclear program, which was agreed under his predecessor Barack Obama's administration.

The "Iran Freedom Policy and Sanctions Act" was introduced by Peter Roskam and backed by Liz Cheney, two Republicans in the US House of Representatives.

The proposed legislation "makes clear what any effective agreement would have to contain," Cheney said in a statement.

A deal with Iran would need to "at a minimum, authorize anywhere, anytime inspections including inspections of military facilities; disclosure of all past and present, military and civilian nuclear activity; a ban on weapons-grade enrichment; and a restriction on ballistic missile development," said Cheney.

The legislation "will ensure that sanctions on Iran will only be relaxed if Iran meets these crucial requirements," said Cheney, criticizing the current agreement for allegedly delivering "sanctions relief and cash payments to the Iranian regime in exchange for unverifiable promises."

A parallel bill aimed at toughening the nuclear deal is under consideration in the Senate.

Trump again waived nuclear-related sanctions last week -- as required every few months to stay in the agreement -- but demanded European partners work with Washington to "fix the deal's disastrous flaws, or the United States will withdraw."

Iran's foreign ministry has said it "will not accept any amendments in this agreement" -- and the International Atomic Energy Agency has confirmed Tehran's compliance with the current agreement.

The other parties to the deal -- Britain, China, France, Germany, Russia and the European Union -- have all said it is working and that Iran is complying fully with its commitments. –AFP