Polish Foreign Minister Witold Waszczykowski said Friday that Russia might respond to the US strike in Syria by escalating fighting in war-torn eastern Ukraine.

“Now everyone is waiting for the reaction from Russia. Either it will react in Syria or, as some say, unfortunately, in Ukraine,” Waszczykowski said on Polish TV.

“There is a certain danger here, because Russia’s policy is unpredictable and in some cases even unreasonable. No doubt, there will be some answer. The only question is where.”

On April 7, the US fired more than 50 cruise missiles at a Syrian airfield in response to Syrian President Bashar Assad’s use of chemical weapons on civilians.

“Despite the strength of the enemy’s army the Ukrainians do not fear Russia and are ready to defend every inch of their land,” Ukrainian Minister of Defense Stepan Poltorak told US congressmen on Thursday.

At least two Ukrainian soldiers have been killed and 22 wounded since the US struck Syria on April 7.

Casualties have decreased this month — compared to 30 Ukrainian soldiers killed and 198 wounded in March — because of a new ceasefire announced on April 1.