A senior U.S. State Department official said on Thursday that there could be an understanding within weeks on how Washington and Tehran might resume compliance with the 2015 Iran nuclear deal.

The official said that this depends on Iran making the political decision to do so.

“Is it possible that we’ll see a mutual return to compliance in the next few weeks, or an understanding of a mutual compliance? It’s possible yes. Is it likely? Only time will tell, because as I said this is ultimately a matter of a political decision that needs to be made in Iran,” the official told reporters in a telephone briefing.