Russian President Vladimir Putin and U.S. President Donald Trump.

Mikhail Metzel | Evelyn Hockstein | Via Reuters

President Donald Trump on Wednesday said he spoke with Russian leader Vladimir Putin for well over an hour about Ukraine's latest attack on Russian airplanes and nuclear talks with Iran.

Putin in that call vowed retaliation against Ukraine for the stunning surprise attack, which Kyiv said resulted in strikes on more than 40 Russian bombers, Trump said.

"It was a good conversation, but not a conversation that will lead to immediate Peace," Trump wrote on Truth Social.

The Kremlin later confirmed the call, which came as fighting continues more than three years after Russia invaded Ukraine.

"President Putin did say, and very strongly, that he will have to respond to the recent attack on the airfields," the president added.

Trump's post did not say if he discouraged Putin from taking that action during their 75-minute conversation.

"We also discussed Iran, and the fact that time is running out on Iran's decision pertaining to nuclear weapons, which must be made quickly!" Trump wrote.

"I stated to President Putin that Iran cannot have a nuclear weapon and, on this, I believe that we were in agreement."

Putin "suggested that he will participate in the discussions with Iran and that he could, perhaps, be helpful in getting this brought to a rapid conclusion," Trump wrote.

The U.S. president said he believes Iran has been "slowwalking" its decision, adding, "we will need a definitive answer in a very short period of time!"

As a presidential candidate, Trump repeatedly vowed that he would bring an end to the Russia-Ukraine war in one day after taking office. But his attempts to swiftly broker peace, or even a lasting ceasefire, have so far failed, and both countries remain far apart on any territorial compromise.

In the meantime, the Biden-era alignment between Washington and Kyiv has frayed, as Trump and his administration have openly criticized Ukraine President Volodymyr Zelenskyy.

Trump's previously careful tone toward Putin has also started to harden, with the U.S. leader recently complaining that the Russian president "has gone absolutely CRAZY!"