Iran effectively abandoned its 2015 nuclear deal with major powers following a U.S. airstrike last week that killed a top Iranian military leader.

The Iranian government said in a statement on Sunday that it would no longer abide by any and all "operational restrictions" on its enrichment of uranium, a key part of the terms of the Joint Comprehensive Plan of Action.

The statement said Iran will no longer comply with the limit on the number of centrifuges, its capacity for enriching uranium, or the level and amount of enrichment.

However, Iran said it was open to negotiations and would willingly return to full compliance with the deal if the U.S. lifts economic sanctions imposed against it. 

The deal has been hanging by a thread since the U.S. withdrew from it in May 2018. Iran has reduced its nuclear commitments in stages since May last year and the latest announcement marks its fifth reduction.