Brussels (AFP) - US Defence Secretary Ashton Carter said Thursday Russia will soon begin to suffer casualties after dramatically expanding its military support for long-time ally, Syrian President Bashar al-Assad.
"This will have consequences for Russia itself which is rightly fearful of attacks ... in coming days, the Russians will begin to suffer from casualties," Carter said at a NATO defence ministers meeting in Brussels dominated by the Syrian crisis.
The secretary told reporters that Russia was backing the wrong horse in Syria and urged President Vladimir Putin to sign up to the US programme of a future without Assad.
Worse still, Moscow was reckless in its military commitment, risking clashes with US and other planes targeting Islamic State (IS) jihadists in Syria.
"They have shot cruise missiles from a ship in the Caspian Sea without warning; they have come within just a few miles (kilometres) of one of our unmanned aerial vehicles," Carter said.
"They have initiated a joint ground offensive with the Syrian regime, shattering the facade that they are there to fight ISIL," he added, using another name for Islamic State.
Damascus announced Thursday it had launched a "vast offensive" to wrest back territory from rebel forces the day after Russia launched a series of unprecedented cruise missile attacks from ships in the Caspian Sea.
NATO diplomatic sources said Moscow had given no advance warning of the missile strikes which came as a complete surprise.
A Syrian general said the Russian intervention had weakened IS and other opponents of Assad but Washington says that more than 90 percent of Moscow's strikes have targeted the moderate opposition backed by the West.
Russia has justified its intervention in Syria as part of global efforts to fight "terrorists" and also to target Russian jihadists who may one day attack their own country.