Russia said on Tuesday it has written guarantees it can carry out its work as a party to the Iran nuclear deal, suggesting Moscow could allow a revival of the tattered 2015 pact to go forward.

Russian Foreign Minister Sergei Lavrov's comments appeared to signal Moscow may have backed off its previous view that Western sanctions imposed on Russia over its invasion of Ukraine were an impediment to salvaging the nuclear deal.

Lavrov on March 5 unexpectedly demanded sweeping guarantees that Russian trade with Iran would not be affected by the Ukraine-related sanctions — a demand Western powers have said was unacceptable and Washington has insisted it will not accept.