President Donald Trump on Sunday announced an “energy ceasefire” between Russia and Ukraine, “effective immediately,” saying both parties had assented to the arrangement.

About an hour earlier, Ukrainian President Volodymyr Zelenskyy had urged President Donald Trump to push for an “energy ceasefire” in the Russia-Ukraine war, speaking to ABC’s Jonathan Karl on “This Week.”

It was not immediately clear whether “both sides” had, in fact, agreed to a ceasefire. After Trump’s announcement, Zelenskyy posted on Facebook: “Ukraine supports the ceasefire, and it is important that Russia support it as well. We are awaiting details from the American side. For our part, Ukraine always FULLY supports steps toward de-escalation, the protection of lives, and the decisions needed to end the war and guarantee lasting peace.”

Meanwhile, Russian state news agency TASS published a Russian-language story about Trump’s social media post, but did not include any statements on the subject from the Russian side. Zelenskyy said later Sunday that Russia struck the CHPP-5 power plant in Kharkiv after Trump’s announcement.