() Ukrainian President Volodymyr Zelenskyy said he spoke with President Donald Trump on the phone about a potential path to end the war with Russia.

“We are grateful to @POTUS for all efforts toward a just and lasting peace. It is truly a must to stop the killing as soon as possible, and we fully support this,” Zelenskyy wrote on social media Tuesday. “Many months could have already passed without war, had Russia not been prolonging it.”

Zelenskyy said he and Trump discussed a recent Russian strike on Kyiv, as well as European aid packages for Ukraine, to which the Netherlands, Sweden, Norway and Denmark have committed.

He also said Ukraine has prepared a draft agreement on drones with the United States and said he was ready “to discuss in detail and conclude it.”

The leaders reportedly also spoke about sanctions on Russia ahead of Trump’s Aug. 8 deadline for a ceasefire.

“Their economy continues to decline, and that’s exactly why Moscow is so sensitive to this prospect and President Trump’s resolve,” Zelenskyy wrote in the post. “This can change a lot.”

The conversation comes as U.S. special envoy Steve Witkoff is set to travel to Moscow on Wednesday in an effort to make progress on a ceasefire.