Israeli President Shimon Peres said Wednesday that the Kremlin has promised to reconsider the planned delivery of powerful air defense missiles to Iran.

Russian President Dmitry Medvedev made the pledge during their talks Tuesday in the Black Sea resort of Sochi, Peres said.

"President Medvedev gave a promise he will reconsider the sales of S-300s because it affects the delicate balance which exists in the Middle East," Peres told reporters via video link from Sochi.

A Kremlin spokesman wouldn't immediately comment on Peres' statement.

Russia has signed a contract to supply the powerful S-300 missiles to Iran, but has dragged its feet on delivering them.

Israel and the United States fear that Iran could use the missiles to protect its nuclear facilities and they have strongly urged Moscow not to supply the weapons. The issue has been the subject of intense diplomatic wrangling for years.

Russian officials confirmed in March that a contract for the missiles had been signed with Iran two years ago, but a top Russian defense official said in April that no deliveries had been made yet.