RUSSIAN President Vladimir Putin warned on Thursday that relations between the United States and Russia will be seriously damaged if Washington supplies long-range missiles to Ukraine.

But President Putin added that even this will not change the situation on the battlefield, where the Russian army is advancing.

The potential supply of US Tomahawk cruise missiles to Kiev will signal a “qualitatively new stage of escalation, including in relations between Russia and the US,” President Putin told a forum of international foreign policy experts in Russia’s Black Sea resort of Sochi.

He said that even though the Tomahawk missiles might inflict some damage on Russia if supplied to Ukraine, Russian air defences will quickly adapt to the new threat. 

“But it will certainly not change the balance of force on the battlefield,” he added.

Asked about US President Donald Trump dismissing Russia as a “paper tiger” because of its failure to defeat its smaller neighbour after more than three years of fighting, Mr Putin argued that Russia has faced all the Nato allies backing Kiev.

“We are fighting against the entire bloc of Nato and we keep moving, keep advancing and feel confident and we are a paper tiger; what Nato itself is?” he said. “A paper tiger? Go and deal with this paper tiger then.”

President Putin went on to hail President Trump's efforts to help negotiate peace in Ukraine and described their August summit in Alaska as productive.

“It was good that we made an attempt to search for and find possible ways to settle the Ukrainian crisis,” he said, adding that he felt “comfortable” talking to President Trump.

Mr Putin also reaffirmed his offer to the US to extend its last remaining nuclear arms control pact for one more year after it expires in February. 

The 2010 New Start treaty limits each country to no more than 1,550 deployed nuclear warheads and 700 deployed missiles and bombers.

“If they don’t need it, we don’t need it either,” he said, adding: “We feel confident about our nuclear shield.”

The Russian president slammed the seizing of ships that carry Russian oil, saying it would amount to piracy and could trigger a forceful response while sharply destabilising the global oil market.

President Putin also warned that Russia was carefully watching the growing militarisation of Europe. 

“Is all of this just words or is it time for us to take countermeasures? No-one should have doubt that Russia’s countermeasures will not take a long time to come.”