Moscow threatens that sending arms to Kiev in retaliation for S-300 missile agreement with Iran will raise the death toll.

Russian President Vladimir Putin has warned Israel against sending arms to Ukraine on Saturday, days after reports emerged that Jerusalem would be in contact with Kiev in retaliation for Moscow lifting a ban on S-300 missile sales to Tehran.

Putin warned in an interview on Russian television that Israeli retaliatory measures would only bring on a new round of violence and raise the death toll in the embattled Donetsk region of eastern Ukraine, which has been the center of a bloody war between the Ukrainian army and pro-Russian separatists for over a year.

“It’s a choice for the Israeli leadership to make, they can do what they see necessary,” Putin said.

Putin signed a decree on Monday lifting a ban on the delivery of S-300 anti-missile rocket systems to Iran.

His latest comments surface days after Prime Minister Binyamin Netanyahu phoned him to express Israel's great concerns over the deal. In the phone call, Netanyahu warned Putin that the sale will increase Iran's aggression in the region and shake the security of the Middle East.

Russia signed a contract in 2007 to supply Iran with five S-300 advanced missile batteries, which can be used against aircraft or guided missiles, at a cost of $800 million.

In 2010, Russia's then-president Dmitry Medvedev cancelled the deal, after the United States and Israel applied strong pressure on him. Both countries worry that the S-300 would make Iran less vulnerable to attack by either one of them, and motivate Iran to develop a nuclear weapon.