Russia, which has been carrying out airstrikes in Syria, said Wednesday it has used four warships in the Caspian Sea to launch rockets at Islamic State targets in the war-torn country.
Defense Minister Sergei Shoigu told President Vladimir Putin that the vessels fired 26 cruise missiles at 11 Islamic State targets that he said were destroyed. He said there were no civilian casualties.
"The results of the strike confirmed the high effectiveness of the missles at great distances – nearly 1,500 kilometers," Shoigu told Putin.
Word of the Russian naval strikes in Syria come as Syrian government forces launched a major ground offensive against rebels under cover of Russian airstrikes.
WATCH: Russian Defense Ministry video alleging launch of cruise missiles against Islamic State targets in Syria
The Britain-based Syrian Observatory for Human Rights, which monitors violence in Syria, said Russian airstrikes Wednesday hit Hama and neighboring Idlib provinces, with Syrian troops using surface-to-surface missiles in the area.
Wednesday's offensive in central Syria and the ensuing clashes with militants, including al-Qaida's Syrian branch, was the first major ground fighting since Moscow began launching air raids in Syria last week.
No US cooperation
Meanwhile, U.S. Defense Secretary Ash Carter told reporters in Rome on Wednesday that the United States, which has conducted thousands of airstrikes against the Islamic State group in Syria and Iraq, has not agreed to cooperate with Russia in the fight against the extremists.
Russia's airstrikes in Syria continue "to hit targets that are not ISIL," Carter said -- using another acronym for the Islamic State – a strategy he called "tragically flawed." Still, he said the U.S. would continue "basic, technical" talks with Russia to ensure the safety of U.S. pilots flying over Syria.
Earlier Wednesday, a spokesman for Russia's Defense Ministry said Russian and U.S. defense experts would meet later in the day to discuss proposals to "coordinate actions in the fight against" Islamic State militants in Syria.
U.S. Secretary of Defense Ashton Carter, center, and Spain's Defense Minister Pedro Morenes, right, walk together during their visit at Moron Airbase, near Seville, Spain, Oct. 6, 2015.
Carter said Tuesday that the two sides held talks last week that were initiated by Russia. He also declined to comment on a U.S. response to Russian warplanes violating Turkish airspace, saying the issue would be covered at a meeting of NATO defense ministers on Thursday.
Turkey reported two violations of its airspace by Russian jets, one Saturday and another Sunday, and twice summoned Russia's ambassador to lodge its complaints. Russian officials have said the incursions happened by mistake.
Russia and Turkey have each talked about the prospect of establishing a joint working group to coordinate and prevent possible incidents related to Russian airstrikes in Syria.
McCain: Russia 'winning'
U.S. Senator John McCain told Alhurra TV that Russian incursions in Turkey's airspace are "very concerning," and equated coordination talks between the U.S. and Russia to appeasement.
McCain, who has long promoted deploying U.S. ground forces to fight Islamic State militants in Iraq and Syria, criticized the way Carter and other members of President Barack Obama's administration have responded to Russian activity in Syria, saying "everybody knows that Russia is winning."
WATCH: Senator John McCain's statement on Russia strikes in Syria
"They have for the first time since 1973 played a major role in the Middle East, and they're achieving all of their objectives while we sit by and call it a quagmire or in the words of the secretary of defense, unprofessional," McCain said. "It has become almost a joke."
Obama authorized an aerial campaign against the Islamic State that has included more than 2,600 airstrikes in Syria and 4,600 in Iraq, but the bombings have had limited success and he has so far ruled out sending American ground troops.
McCain said it is "obvious" Russia is targeting moderate opposition fighters and not the Islamic State with its own airstrikes that began last week, and criticized as "outrageously immoral" the failure of the U.S. to protect the Syrian rebels it has trained and equipped.
"We should say to the Russians we are going to fly anywhere we want to at any time and you better not get in the way," he said.
Some material for this report came from AP.