MOSCOW, December 20. /TASS/. The war on terrorism must be uncompromising and merciless, Russian Foreign Minister Sergey Lavrov said at a meeting with his Iranian counterpart Mohammad Javad Zarif on Tuesday.

"We are grateful for the manifestations of solidarity over the terrorist attack that claimed the life of Russian ambassador Andrey Karlov. We have been hearing condolences from all countries around the world," he said. "We feel that this barbaric crime is a fresh reminder the war on terrorism must be uncompromising and merciless," Lavrov said.

The attempts to connect terrorist attacks to Russia’s support for Damascus in its war on terror are unacceptable, Lavrov said. According to Lavrov, these attempts are aimed at shielding the militants.

"This a provocative, perverse and unacceptable logic, these people are trying to protect terrorists and stop the fight against them," Lavrov added. "The attempts to make the world believe that the support of the legitimate Syrian regime only increases the terrorist threat, are absolutely unacceptable."

The masterminds of the murder of the Russian ambassador in Turkey will fail to thwart the struggle against terrorism, according to Lavrov.

"If the organizers of this terrorist attack intended to thwart the fight against terrorism and our meeting (the trilateral meeting of the Russian, Iranian and Turkish foreign ministers), in particular, they have failed to do this and will fail," Lavrov said

Russia’s ambassador to Turkey, Andrey Karlov, was gunned down on December 19 as he was speaking at the opening of a photo exhibition Russia from Kaliningrad to Kamchatka through a Traveler’s Eyes. The Turkish authorities identified the attacker as former police officer Mevlut Mert Altyntash. He was promptly eliminated by the local security forces. The attacker had injured three other persons. The Russian Foreign Ministry has qualified the attack as an act of terrorism.