Iranian state television says letters outlining the Islamic Republic's partial withdrawal from its 2015 nuclear deal with world powers have been delivered to ambassadors.

State TV made the announcement Wednesday. It did not elaborate on what steps Iran planned to take.

The letters were to be delivered to the leaders of Britain, China, the European Union, France and Germany. All were signatories to the nuclear deal, which saw Iran limit its enrichment of uranium in exchange for the lifting of economic sanctions. A letter was also to go to Russia.

The move came a year to the date President Donald Trump withdrew America from the accord.

The letters will come as officials in the Islamic Republic previously warned that Iran might increase its uranium enrichment, potentially pulling away from a deal it has sought to salvage for months.