We reported earlier that the Ukrainian side seemed to react positively to former President Donald Trump's phone call with President Zelensky on Friday, as the Republican nominee for president conveyed that upon taking the White House his priority will be to explore achieving peace with Russia.

Trump wrote in the call aftermath that "I, as your next President of the United States, will bring peace to the world and end the war that has cost so many lives and devastated countless innocent families." He added that "Both sides will be able to come together and negotiate a deal that ends the violence and paves a path forward to prosperity."

But some influential Ukrainian officials are already warning Zelensky against too hastily taking to the negotiating table. Zelensky has in the past consistently rejected the idea of sitting down with Moscow, and has openly stated he intends to refuse so long as Putin is leader of Russia.

But amid ongoing devastating troop losses, lack of artillery ammunition compared to much better-armed Russian forces, and a general war fatigue setting in, Zelensky could eventually welcome the kind of opening toward peace that a potential Trump presidency provides.

Kyiv's mayor said on Sunday that Zelensky risks "political suicide" should he pursue a peace deal which ends in Ukraine ceding territory to Russia. 

Mayor Vitali Klitschko said in an interview with the Italian daily Corriere della Sera on Sunday:

"How can we explain to the country that we need to give up pieces of our territory that cost the lives of thousands of our fighting heroes? Whatever move he makes, our president risks political suicide."

He admitted that the coming few months will be "very difficult" for Zelensky, and that the Ukrainian populace will want a say in the country's fate. So the scenario of holding a referendum on the question of a deal with Moscow would be likely at some future point.

"I don't think he can reach such painful and important agreements on his own without popular legitimization," Klitschko said of the question of territorial concessions. He said this could be a "way out" for Zelensky, as well as the creation of a national unity government.