By Vladimir Soldatkin
SOCHI, Russia (Reuters) -Russian President Vladimir Putin swiped back on Thursday at U.S. President Donald Trump for calling Russia a "paper tiger", suggesting NATO might be one and warning the United States that if it supplied Tomahawk missiles to Ukraine it would trigger a dangerous new escalation.
Russia's war in Ukraine, Europe's deadliest since World War Two, has sparked the biggest confrontation between Russia and the West since the Cuban Missile Crisis in 1962, and Russian officials say they are now in a "hot" conflict with the West.
Putin, speaking at the Valdai Discussion Group in the Black Sea resort of Sochi, said that Russian forces were advancing along the entire front in Ukraine and that almost all of the U.S.-led NATO alliance was now fighting against Russia.
Trump, who had previously said Kyiv should give up land to make peace with Moscow, reversed his rhetoric sharply last week, saying he thought Ukraine could win back all territory from Russia, and labelling Moscow a "paper tiger". He repeated the line this week.
"A paper tiger. What follows then? Go and deal with this paper tiger," Putin said. "Well if we are fighting with the entire NATO bloc, we are moving, advancing, and we feel confident, and we are a 'paper tiger', then what is NATO itself?"
Putin poured irony on European claims that Russian drones had invaded NATO airspace, quipping that he promised he would not do it again in Denmark and that he did not have drones that could fly to Lisbon.
European authorities have accused Russia of brazen violations of the region's airspace, including with recent incursions by drones over Poland and fighter jets over Estonia.
He took a more serious tone about the possibility of the United States supplying Tomahawk cruise missiles to Ukraine, saying that such a step would lead to a dangerous new wave of escalation.
"It is impossible to use Tomahawks without the direct participation of American military personnel," Putin said. "This will mean a completely new, qualitatively new stage of escalation, including in relations between Russia and the United States."
The United States has so far not announced any decision on supplying Tomahawks to Ukraine.
'COOL DOWN, SLEEP CALMLY,' PUTIN TELLS NATO
NATO members, he said, were providing Ukraine with intelligence, weapons and training, and whipping up what he cast as hysteria about alleged plans of Russia to attack a NATO member, which he dismissed as "impossible to believe".
"If anyone still has a desire to compete with us in the military sphere, as we say, feel free, let them try," Putin said. "Russia's countermeasures will not be long in coming."
Putin portrays the war as a watershed moment in Moscow's relations with the West, which he says humiliated Russia after the 1991 fall of the Soviet Union by enlarging NATO and encroaching on what he considers Moscow's sphere of influence.
Western European leaders and Ukraine cast the war as an imperial-style land grab and have repeatedly vowed to defeat Russian forces. They argue that unless Russia is defeated, Putin will risk an attack on a NATO member.
"I just want to say: Cool down, sleep calmly, and take care of your own problems. Just take a look at what's happening on the streets of European cities," Putin said.
Putin said Ukraine's armed forces had a grave lack of manpower and desertions, while Russia had enough soldiers. He suggested that Kyiv should negotiate an end to the war.
Russia, he said, controlled almost all of Luhansk province, about 81% of the Donetsk region, and about 75% of both Zaporizhzhia and Kherson regions.
(Reporting by Vladimir Soldatkin and Reuters reporters in Moscow and London; Writing by Lucy Papachristou and Guy Faulconbridge; Editing by Mark Trevelyan, Andrew Osborn, Cynthia Osterman and Daniel Wallis)