Putin says 'nothing compromising' in Trump call to Ukraine leader
President Donald Trump's manner with Russian leader Vladimir Putin was in contrast to the anger he flashed at NATO allies. (AFP / Brendan Smialowski)

Russian President Vladimir Putin on Wednesday defended Donald Trump over accusations the US leader pressured Kiev to dig up dirt on a rival, saying there was "nothing compromising" in transcripts of the call.

"I see nothing compromising in the conversation between Trump and (Ukrainian leader Volodymyr) Zelensky," Putin said of the phone call that has sparked an impeachment probe in the US.

"President Trump turned to a colleague with a request to investigate possible corruption relating to members of the former administration," the Russian leader said at an energy forum in Moscow.

"Any head of state would have had to do the same."

"They have already been using any excuse to attack President Trump. Now it's Ukraine," Putin added.

The White House last week released a transcript of the July call with a recently elected Zelensky.

It showed that Trump asked Zelensky to probe Democratic rival Joe Biden, and the Democrats are looking into whether Trump used a delayed $400 million (365.8 million euros) aid package as leverage.

Ukraine is fighting an ongoing war in its east against Russia-backed separatists, which broke out after Moscow's annexation of Crimea in 2014.