NATO Secretary General Mark Rutte warned members of the transatlantic alliance on Thursday that they could be Russia’s next target.
Rutte, Donald Trump’s calls to take more steps to bolster its security.
Rutte told attendees that the move wasn’t a moment for self-congratulations as Russia continues its large-scale drone and missile attacks on Ukraine.
"I fear that too many are quietly complacent. Too many don't feel the urgency. And too many believe that time is on our side. It is not. The time for action is now," he said.
The NATO chief urged allies to boost defense spending and production, saying their armed forces must have the resources needed to protect their homelands, and cautioning that Moscow could be ready to use military force against NATO within five years.
"We must all accept that we must act to defend our way of life, now. Because this year, Russia has become even more brazen, reckless and ruthless towards NATO and towards Ukraine," Rutte added. "During the Cold War, President Reagan warned about the aggressive impulses of an evil empire. Today, President Putin is in the empire building business again."
Poland accused Russia of being responsible for a railway blast on its Warsaw-Lublin line in November.
Prime Minister Donald Tusk said an investigation into the incident found that Russian Secret Services "commissioned the blast of the Polish railway and recruited two Ukrainians to do it."
The railway blast was the latest in a string of security incidents in Eastern Europe, following airspace incursions in September that saw Russian drones enter Poland and three MiG-31 fighter jets cross into Estonia before being intercepted by NATO aircraft.