ROME The United States on Wednesday ruled out military cooperation with Russia in Syria's war, accusing Moscow of pursuing a "tragically flawed" strategy that would force it to limit military talks to basic pilot safety.
U.S. Defense Secretary Ash Carter's critique amounted to a rebuff of Russia, which had sought greater coordination as Moscow escalates its military role in support of Syrian President Bashar al-Assad.
"We are not prepared to cooperate in a strategy, which as we explained, is flawed - tragically flawed - on the Russians' part," Carter told a news conference during a trip to Rome.
The United States and its allies have been waging a year-long air campaign against Islamic State in Syria, while pushing to diplomatically edge Assad from power.
Russia launched its air campaign last month saying it would also target Islamic State. But its planes have also hit other rebel groups opposed to Assad, Moscow's longtime ally, including groups backed by Washington.
"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 said.
"What we will do is 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."
The United States has put forward various proposals, including simple safety protocols, such as maintaining a safe distance between U.S. and Russian aircraft and using common radio frequencies for distress calls, officials say, adding they would be similar to regulations found in civil aviation.
In a reminder of the risks, U.S.-led coalition aircraft bombing Islamist militants in Syria were re-routed at least once in the last six days to avoid a close encounter with Russian planes, the Pentagon said.
Russia's deputy defense minister, Anatoly Antonov, was quoted by the Tass news agency on Tuesday as saying the Russian military agreed in principle with the proposals made by the United States on coordinating military flights.
He said the two countries would hold a second joint video conference on the subject in the "coming days."
But U.S. defense official said Washington had not yet heard back formally from Russia on the proposals themselves, something that would be normally done in writing before any meeting.
Efforts to ensure pilot safety have gained urgency after the United States and NATO denounced Russia for violating Turkish airspace. Turkey, a NATO ally, threatened to respond, raising the prospect of direct confrontation.
Russian aircraft twice entered Turkish air space at the
weekend, and Turkey says an unidentified MIG-29 harassed its jets on Monday, prompting the foreign ministry to summon the Russian ambassador three times in protest.
(Reporting by Phil Stewart and Crispian Balmer in Rome; Yeganeh Torbati in Washington; Editing by Alison Williams and Cynthia Osterman)