KYIV (Reuters) - President Volodymyr Zelenskiy has said Ukraine must do all it can to ensure the war with Russia ends next year through diplomacy.

In a radio interview aired on Saturday, Zelenskiy conceded that the battlefield situation in eastern Ukraine was difficult and Russia was making advances. He said his Russian counterpart Vladimir Putin was not interested in agreeing to a peace deal.

Zelenskiy said U.S. legislation prevented him from meeting President-elect Donald Trump before his inauguration next January. The Ukrainian leader said he would only talk with Trump himself rather than any emissary or advisor.

"I, as the president of Ukraine, will only take seriously a conversation with the president of the United States of America, with all due respect to any entourage, to any people."

"From our side, we must do everything so that this war ends next year, ends through diplomatic means," Zelenskiy said.

(Reporting by Max Hunder; Editing by Kevin Liffey)