A day after the Russian navy fired cruise missiles at targets in Syria — and two days after Russia's warplanes veered into Turkey's airspace — NATO Secretary-General Jens Stoltenberg says the alliance "is able and ready to defend all allies, including Turkey, against any threat."

Speaking at nearly the same time, Syrian Deputy Foreign Minister Faisal Mekdad said, "Russia's joining the struggle against terrorism on Syria's territory will lead to changes in the region and the whole world," in remarks relayed by Russia's Tass news agency .

At a summit of NATO defense ministers, Stoltenberg said Russia has ratcheted up tensions in the area since its military began carrying out attacks to support Syrian President Bashar Assad. And he dismissed Russia's explanation that it had been patrolling Turkey's border as a way to help the country.

"Turkey is a strong ally. Turkey has the second-largest army in the alliance," Stoltenberg said.

Russia launched a series of cruise missiles from its ships Wednesday, supporting a new push by Syrian government troops. Parts of the offensive were broadcast on TV , showing missiles streaking toward their targets.

Today, Syrian rebels are claiming to have forced down a Russian helicopter.

"An amateur video shows two helicopters descending at low altitude," NPR's Alison Meuse reports. "The crafts are close enough to the front lines in central Syria for activists to catch the emergency landing on camera. Activists say the helicopter landed in a regime-held town — miles from the nearest military airport."

Alison adds that the new ground and air campaign in Hama province has met with strong resistance.

"Rebels claim to have destroyed more than 15 regime tanks in the past day," she says, "with TOW missiles supplied by the US and its allies. Activists say Russian and Syrian warplanes have retaliated with fierce bombardments."

Russia says the missile attacks hit nearly a dozen ISIS targets — and the country says the attacks haven't harmed civilians.

NPR's Corey Flintoff reports:

"From the very start of this bombing campaign, the Russians have strongly denied causing any civilian casualties. Russian officials are accusing Islamic State fighters of hiding among the civilian population, and they say Russian warplanes have canceled attacks whenever there was a possibility of hurting non-combatants."

NATO, U.S. officials and others have noted that Russia has targeted U.S.-backed rebels who are fighting Assad, rather than focusing on ISIS strongholds as the country initially declared it would do.

As Defense Secretary Ash Carter traveled to Brussels for Thursday's session, he "ruled out cooperation with Russia in Syria," Teri Schultz reports for NPR's Newscast, with Carter saying Moscow is following the "wrong strategy."

Carter said he wants the U.S. and Russia to coordinate their operations in the region only to avoid possible collisions in Syria's airspace.

In his speech kicking off the NATO meeting, Stoltenberg also said the alliance will establish two "small headquarters" in Hungary and Slovakia, two countries that have been caught up in the refugee crisis that has sent thousands of people into Europe this year.

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