Putin addressed his remarks to military officials as Russia pressed for an urgent U.S. and NATO reply to proposals it made last week for a binding set of security guarantees from the West.
"What the U.S. is doing in Ukraine is at our doorstep... And they should understand that we have nowhere further to retreat to. Do they think we’ll just watch idly?" Putin said.
"If the aggressive line of our Western colleagues continues, we will take adequate military-technical response measures and react harshly to unfriendly steps."
Putin did not spell out the nature of these measures but his phrasing mirrored that used previously by Deputy Foreign Minister Sergei Ryabkov, who has warned that Russia may redeploy intermediate-range nuclear missiles in Europe in response to what it regards as NATO plans to do the same.
Russia rejects Ukrainian and U.S. accusations that it may be preparing an invasion of Ukraine as early as next month by tens of thousands of Russian troops poised within reach of the border.
It says it needs pledges from the West - including a promise not to conduct NATO military activity in Eastern Europe - because its security is threatened by Ukraine's growing ties with the Western alliance and the possibility of NATO missiles being deployed against it on Ukrainian territory.
Ukrainian President Volodymr Zelenskiy said on Friday that he was ready to meet Russia for "direct talks, tête-à-tête, we don't mind in what format". But Moscow has said repeatedly it sees no point in such a meeting without clarity on what the agenda would be.
A Kremlin statement said Putin stressed in a phone call with French President Emmanuel Macron that reconvening the four-power Normandy group - which brings together the leaders of Russia, Ukraine, France and Germany - would require concrete steps by Kyiv to implement existing peace agreements. Ukraine says it is Russia and its proxies who are refusing to engage.
With Western powers keen to show Russia they are solid in their support of Ukraine and NATO, Germany's new Chancellor Olaf Scholz also spoke by phone with Putin.
U.S. Secretary of State Antony Blinken on Tuesday ruled out an in-person meeting between Biden and Putin for now. "I think we have to see if, in the first instance, there’s any progress diplomatically," Blinken said in a news briefing when asked if an in-person summit could happen to try to ease the tensions.
