Gdánsk, Poland — Poland's Deputy Prime Minister Radek Sikorski told CBS News in an interview that he would not rule out the possibility of Russia staging a "false flag operation" in the next two years to justify an attack on a NATO member state. 

"I wouldn't exclude the Russians doing some kind of false flag operation against Russian territory in order to have a pretext for hitting one of the NATO countries," Sikorski said. "We need to communicate to [Russian President Vladimir] Putin that we know what he's up to and that we will not be taken in and that this would be completely unacceptable, and we would defend every inch of NATO territory."

Sikorski said he believes Ukraine's successful resistance — which analysts say has even started to change the tide of the war in Kyiv's favor this year — has so far deprived Russia of the resources it would need to mount an effective invasion of NATO's eastern flank. 

"Ukraine has certainly won in the Black Sea. Russia certainly doesn't have air domination over Ukraine. It can send missiles and drones, but it cannot fly freely over Ukraine. The ground war is stuck, and Ukraine seems to have gained fire control over a strategic highway from Donbas to Crimea," he said. "Wars are never linear. They go through phases. But it looks like the phase of Russia having the initiative has ended."

Ukrainian forces have retaken more than 230 square miles of territory this year, according to Ukraine's top general, and attacks on energy infrastructure forced Russian authorities to cut off gas sales last week to civilians in Crimea, the Ukrainian peninsula that has been occupied by Russia since 2014.

Poland continues to play a crucial role in Ukraine's defense. Estimates suggest 90% of foreign military supplies for Kyiv travel across the Poland-Ukraine border. But relations between the two nations have frayed recently over a Ukrainian decision to rename a military unit in honor of a World War II-era Ukrainian militia remembered in Kyiv for fighting off the Soviet Union — but in Poland for the ethnic cleansing of Polish civilians in the Volhynia massacre of 1943. 

Sikorski said the neighboring countries must move past the dispute to focus on their common enemy in Moscow. 

"It's not about people falling into each other's arms. It's about deciding not to repeat the bad stuff and to find a better common future. And it's in that spirit that I hope we'll be able to handle the relationship with Ukraine," Sikorski said. "We shouldn't allow Putin to take advantage of our disagreements."

Russia's Foreign Minister Sergey Lavrov told reporters this week that Moscow was "ready to talk with Kyiv, as ⁠we have always been." 

Sikorski said any future discussions should be held directly between Ukraine's President Volodymyr Zelenskyy and Putin, without third parties mediating. 

"I'm personally of the view that it's better to allow Russia and Ukraine to negotiate directly. They negotiate over exchanges of bodies of fallen soldiers, of POWs. And there are issues that we don't want to be pressing them to do," he said. 

The last time Russian and Ukrainian representatives met face to face was in February in the United Arab Emirates during trilateral summits mediated by the United States. 

"We Europeans are not neutral between the two sides. We are on the side of the victim of aggression. And Russia is the aggressor," Sikorski told CBS News on Thursday. 

"The United States also helps, not as much as in the past, but it's also helping Ukraine," he said. "We think that if Putin is ready for a ceasefire, which has been offered by Ukraine, or for a peace deal, he will find Zelensky's number."