The Russia-Ukraine war will not finish quickly when Donald Trump enters the White House, despite the president-elect's vow to end the conflict on his first day in office, former Ukrainian Foreign Minister Dmytro Kuleba told CNN's "Fareed Zakaria GPS" Sunday.

Kuleba, who was President Volodymyr Zelenskyy's foreign minister from March 2020 until stepping down in September, said there were three major reasons that a quick solution is unlikely.

"What I know for certain is that first, Zelenskyy will not leave under pressure," he said. "Second, Ukraine will not agree to any quick solution. And third, most importantly, I would like to remind everyone that the key to peace lies in Moscow not in Kyiv."

When asked if there were concerns in Kyiv that Trump would demand Ukraine accept a peace deal that would require it to give up the territory now occupied by Russian forces, which amounts to about a fifth of Ukraine, Kuleba said the question needs to be flipped around to what Russian President Vladimir Putin would conceivably accept in order to have a cease-fire.

"With utmost respect, we should not start the conversation with what Ukraine is ready to accept. We should put full responsibility on the side that launched this war," Kuleba said.

Kuleba acknowledged that the Russians' use of more lethal weaponry, including new ballistic missiles in the war, has frightened his countrymen.

"I will not conceal that people in Ukraine are nervous about this latest, latest strike," he said, adding that Ukrainians are also very concerned about "the announcements by Putin that other strikes with intercontinental missiles will follow."