Ukrainian President Volodomyr Zelenskyy promised Sunday that his country can still win the war against Russia, provided that the United States and other allies continue to provide the military aid it needs to challenge Moscow’s air power and ultimately push its troops out of the country.

“I don’t think that this is a stalemate,” Zelenskyy said in an interview with NBC News, a comment that comes as even some of Ukraine’s top military commanders have acknowledged the country’s summer counteroffensive has not yet resulted in major gains, despite inflicting staggering losses on Russia.

That lack of progress has prompted some of Ukraine’s allies to suggest the conflict could end with peace negotiations, not outright victory, a proposal rejected by many Ukrainians who fear that Russia would just exploit any suspension in fighting to regroup.

To shore up support in light of growing fatigue with the war, at least in Congress, pro-Ukraine activists, including a Ukrainian soldier, recently descended on Washington to urge lawmakers — primarily Republicans — to continue aiding Kyiv’s war effort.

Zelenskyy, speaking Sunday, said that US support is needed to help Ukraine get through the winter. In particular, he acknowledged that his country is lacking air power, specifically drones and air defense systems. Experts recently told Insider that Ukraine, despite having an early lead, has fallen behind Russia when it comes to utilizing unmanned aerial vehicles, or UAVs.

The Ukrainian president argued that such support would be rewarded with battlefield success, claiming his country’s armed forces plan to use new tactics in the months ahead.

“Our military are coming up with different plans, with different operations in order to move forward faster and to strike [the] Russian Federation unexpectedly,” he said.