President Zelensky / REUTERS

"Time is ticking," he told the Guardian in a rare interview, to be published in full on Saturday. "The government can spend one year on the entire agreement. Then it should be implemented. Any longer is prohibited."

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Zelensky gave a deadline of a year from December's first summit with Putin to find a breakthrough. "I won't give my five years, which were given to me by the Ukrainian people, to work on Minsk for five years. I won't do it," he said, adding there were "two or three plans" of what to do after walking away from talks, but declining to elaborate.

He said the peace negotiations were a distraction from his domestic agenda, which has been hampered by political infighting that culminated in his decision this week to oust the prime minister.