House Speaker Paul Ryan is calling on the Obama administration to rule out the possibility Iran will be given access to the dollar and the U.S. financial system.

The Wisconsin Republican on Thursday criticized Secretary of State John Kerry for leaving the door open for Tehran to score what he describes as an unprecedented economic windfall as part of sanctions relief from the landmark nuclear deal.

Administration officials have said repeatedly Iran will not get access to the dollar.

But Ryan says Kerry didn't definitively say no when he had the opportunity to do so earlier this week.

Ryan's remarks come after House Foreign Affairs Committee Chairman Ed Royce of California introduced a bill that prohibits the administration from allowing the dollar to be used in trade transactions with Iran.