Russia and Belarus are ready to act preemptively over increased military escalation from European countries over Ukraine, the head of Russia’s foreign spy service chief said Tuesday, according to state media.

“We feel and see that European countries, especially France, Great Britain and Germany, are increasing the level of escalation around the Ukrainian conflict. Therefore, we need to act preemptively. We are ready for this,” Sergei Naryshkin was quoted as saying by both the TASS and RIA news agencies.

In the event of an attack on Russia or Belarus, Russia would retaliate against NATO as a whole, but that Poland and the Baltic states would suffer first, he added.

Those countries should understand that “in the event of aggression” from NATO “damage will certainly be inflicted on the entire NATO bloc, but to a greater extent the first to suffer will be the bearers of such ideas in the political circles of Poland and the Baltic countries,” Naryshkin said.

His comments came days after Steve Witkoff, the U.S. special envoy leading talks with the Kremlin, met with President Vladimir Putin in the Russian city of St. Petersburg, amid American attempts to broker a ceasefire in the war that entered its fourth year in February.

Ukrainian President Volodymyr Zelenskyy also warned Sunday that Putin could attempt to seize NATO territory if he is not stopped in Ukraine.

“If we do not stand firm, he will advance further,” Zelensky said during an interview broadcast on CBS, adding that Putin’s long-term objectives included restoring the Russian empire that would include parts of NATO-allied countries.

“Considering all of this, I believe it could escalate into a world war,” he said.

His concerns echoed those of NATO Secretary General Mark Rutte, who said in February that “if Putin attacks NATO, the reaction will be devastating. He will lose.”