Russia insists its warplanes are targeting Islamic State militants
Nato defence
ministers will assess the "troubling escalation of Russian military
activities" in Syria, the alliance's secretary-general says, ahead of
talks in Brussels.
Jens Stoltenberg says he is concerned about
Russia's use of cruise missiles as well as air strikes, but Nato is
ready to defend all allies.
Nato member Turkey says Russian jets have violated its airspace recently.
Mr Stoltenberg urged Moscow to stop backing Syrian leader Bashar al-Assad.
Moscow
denies Western accusations that it has mainly targeted Assad opponents,
insisting its strikes have hit Islamic State (IS) infrastructure, and
other militant groups.
A US-led coalition has been carrying out
air strikes against IS in both Syria and Iraq for months. But Western
countries support rebels who have been fighting to oust Mr Assad since
2011.
Analysis: Sarah Rainsford, BBC Moscow correspondent
Russia
wants to show that Western policy in Syria has failed and there are
other forces to be supported there, primarily President Bashar al-Assad.
The Kremlin's desire appears to be aimed at keeping America on the back foot.
The
use of cruise missiles on Wednesday does not change the situation
militarily - the same effect could have been achieved by air strikes.
But Mr Putin wants to project his power on the world stage, to show that he is a force to be reckoned with.
Nato ministers are meeting amid a deepening sense of crisis, says BBC defence correspondent Jonathan Marcus.
They
are expected to express their solidarity with Turkey as well as to
address increased concern among Baltic member states following Russia's
involvement in eastern Ukraine.
Nato,
Mr Stoltengerg said, "has already responded by increasing our capacity,
our ability our preparedness to deploy forces, including to the South,
including in Turkey, if needed".
UK Defence Secretary Michael Fallon is expected to announce that
Britain is ready to make a long-term troop deployment to the Baltic republics, our correspondent says.
On
Wednesday, Russia said it had launched missile strikes against IS from
warships in the Caspian Sea - about 1,500km (930 miles) away.
Russia's
foreign ministry also said Moscow was willing to establish contact with
the Free Syrian Army - a Western-backed rebel group - to discuss
fighting IS "and other terrorist groups".
But US Defence Secretary Ash Carter said coalition forces fighting IS in Syria would not co-operate with Russia.
"We believe Russia has the wrong strategy," he said. "They continue to hit targets that are not IS."
Airspace violations
Russia's
air campaign in Syria has raised fears of accidental contact between
Russian warplanes and those of the US-led coalition which have been
targeting IS for the past year.
Pentagon officials revealed they
recently had to carry out at least one "safe separation" manoeuvre to
avoid a US jet coming too close to a Russian aircraft over Syria.
Russia's envoy to Ankara was summoned three times in response to recent incursions into Turkey's airspace.
Turkish President Recep Tayyip Erdogan warned the Kremlin that any "attack on Turkey means an attack on Nato".
"If
Russia loses a friend like Turkey, with whom it has a lot of
co-operation, it is going to lose a lot of things. It needs to know
this," Mr Erdogan said.
The Syrian civil war began with an
uprising against President Assad in 2011 that was brutally put down. It
has since deteriorated into fighting between pro-government forces and
various rebel groups - some of which also fight each other.
Amid the chaos, IS militants have seized swathes of territory in Syria and Iraq.
