Rasmussen said he believes that Europe has demonstrated the ability to carry out the necessary volume of arms supplies, but "it is not time to rest, as this war is far from over."
Read also: Putin prepares for another offensive to conquer Ukraine, NATO's Stoltenberg warns
He noted that after Putin's failure in his attempts to divide and intimidate Ukraine and the West, the Russian dictator is now trying to exhaust them.
"Russia responded to Ramstein's decision by increasing attacks on Ukrainian cities," the former NATO chief said, referring to the latest meeting of Ukraine's military allies, shortly after which it was announced that Ukraine would be supplied with modern main battle tanks.
Read also: Ukrainian commander says any Russian offensive from Belarus will fail
"So, instead of preparing for a spring offensive, we must act in response to the inevitable offensive now. Putin and his commanders know that the window of opportunity on the battlefield is closing, and they will exert maximum pressure."
In an interview with UK news magazine the Economist in December, Ukrainian Commander-in-Chief Valerii Zaluzhnyi said that Russia could launch a new major offensive in February. He said it could start, in particular, from the territory of Belarus in the direction of Kyiv.
Ukrainian Defense Minister Oleksii Reznikov has also predicted that a new large-scale offensive by Russian troops would begin in the spring.
Read also: Russia unlikely to succeed in its spring offensive, experts say
A representative of Ukraine's Defense Intelligence, Vadym Skibitsky, said that as part of Moscow's preparations for a new offensive, Russian troops are regrouping on all sections of the front line.
On Jan. 30, President Volodymyr Zelenskyy stated that despite the Kremlin's plans, Ukraine would defeat the enemy troops and prepare its own major counteroffensive.