United States Defense Secretary Ash Carter said Wednesday that the U.S. will not cooperate militarily with Russia in the fight against the Islamic State group due to Moscow's "tragically flawed" strategy in Syria, reports Reuters.

"We are not prepared to cooperate in a strategy which as we explained is flawed, tragically flawed on Russia's part," Carter said during a trip to Rome.

Russia backs Syrian President Bashar al-Assad and began an air campaign in the country last month with the goal of destroying both the Islamic State group and the rebels fighting to remove Assad from power. Moscow's involvement has agitated Washington because the U.S. has been arming and funding many of those rebel groups and contends that the only way to achieve peace in Syria is to oust Assad.

"Despite what the Russians say, we have not agreed to cooperate with Russia so long as they continue to pursue a mistaken strategy and hit these targets," Carter added.

Carter said the U.S. will, however, "continue basic, technical discussions on professional safety procedures for our pilots flying [over] Syria. That is it. We will keep the channel open because it is a matter of security and safety for our pilots."

Russia's Deputy Defense Minister Anatoly Antonov said on Tuesday that Russia is willing to continue safety talks, but he added that the talks should be much broader and include discussions on international cooperation between Russia and the U.S. so that the Islamic State can be defeated, according to the Star Tribune.

But "regrettably, the Americans would like to limit our cooperation to technical issues relating to interaction between our pilots," Antonov said.

On Wednesday, Russia conducted a major offensive against the Islamic State group in central Syria. Four Russian warships in the Caspian Sea fired 26 long-range cruise missiles at 11 targets, with the missiles traveling 930 miles through Iranian and Iraqi airspace, according to the Guardian.

"According to objective control data, all the targets were destroyed. No civilian objects sustained damage," said Russia's Defense Minister Sergey Shoigu, reported RT.

Also on Wednesday, Russia and Syria launched coordinated attacks against opposition rebel groups in various towns in the western Syrian provinces of Idlib and Hama. Russian fighter jets reportedly bombed a series of targets as Assad forces attacked from the ground, according to CNN.