Vladimir Putin has said he hopes nuclear warheads will not be needed to deal with terrorists or anyone else, after Russia launched cruise missiles from its submarine at Syria.
During a meeting in the Kremlin, Russia’s Defence Minister Sergei Shoigu told the President that Kalibr cruise missiles had been fired by the submerged Rostov-on-Don submarine from the Mediterranean Sea for the first time.
He said TU-22 bombers also took part in the latest raids and that "significant damage" had been done to a munitions depot, a factory manufacturing mortar rounds and oil facilities. Two major targets in Raqqa, the defacto capital of Isis, had been hit, said Mr Shoigu.
President Putin said the new cruise missiles could also be equipped with nuclear warheads - but that he hoped they would never need them.
He said: "With regard to strikes from a submarine. We certainly need to analyse everything that is happening on the battlefield, how the weapons work. Both the [Kalibr] missiles and the Kh-101 rockets are generally showing very good results. We now see that these are new, modern and highly effective high-precision weapons that can be equipped either with conventional or special nuclear warheads."
"Naturally, we do not need that in fighting terrorists, and I hope we will never need it. But overall, this speaks to our significant progress in terms of improving weaponry and equipment being supplied to the Russian army and navy."
Mr Shoigu said Israel and the US had been informed before the strikes were launched.
Russia's air campaign has been taking place since 30 September.
Russian Foreign Minister Sergey Lavrov later sought to temper any suggestion the country would use nuclear weapons on terrorists.
"Of course not, and the president has stated this, that there is no need to use any nuclear weapons against terrorists, as they can be defeated through conventional means, and this is fully in line with our military doctrine," he said.
Additional reporting by AP