Following Ukraine's major drone attack deep on air bases inside Russia, Trump reported that Putin told him Russia "will have to respond".
Trump also warned in a social media post that the phone call, which lasted more than an hour, would not "lead to immediate Peace".
The two leaders also discussed Iran, and Putin suggested he could help with nuclear talks with the country.
The conversation between the two leaders marks the first since Ukraine launched an audacious attack striking Russian air bases on 1 June, targeting nuclear-capable long-range bombers.
In his post, Trump said that Putin told him - "very strongly" - that he "will have to respond to recent attacks on the airfields."
Last week, Trump appeared to set a two-week deadline for Putin, threatening to change how the US is responding to Russia if he believed Putin was still "tapping" him along on peace efforts in Ukraine.
The comment was one of a string of public critical remarks by Trump, who earlier had said that Putin had gone "absolutely crazy" and is "playing with fire" when Russia intensified drone and missile attacks on targets in Ukraine.
Trump made no mention of a deadline or his previous remarks in Wednesday's post on his Truth Social platform.
The post also comes just days after a second round of direct peace talks between the warring sides, held in Istanbul, ended without a major breakthrough, although the two sides agreed to swap more prisoners of war.
Ukrainian negotiators said Russia rejected an "unconditional ceasefire" - a key demand of Kyiv and its Western allies including the US.
The Russian team said they'd proposed multi-day ceasefires in "certain areas" of the frontline in Ukraine, although they gave no further details.
Trump has previously - and repeatedly - said he believes the two sides are making progress, despite ongoing fighting on the frontline and aerial attacks carried out in both Russia and Ukraine.
Additionally, Trump said that on the call he and Putin discussed Iran, and he believed the two "were in agreement" that "Iran cannot have a nuclear weapon".
The US reportedly proposed Iran halt all production of enriched uranium - which can be used to make reactor fuel but also nuclear weapons - and instead rely on a regional consortium for supplies. Iran has not yet responded to the plan presented at talks last Saturday.
According to Trump, Putin "suggested that he will participate in discussions with Iran and that he could, perhaps, be helpful in getting this brought to a rapid conclusion."
"It is my opinion that Iran has been slow walking their decision on this very important matter," Trump wrote. "We will need a definitive answer in a very short period of time."
US President Donald Trump said that Russian President Vladimir Putin told him “very strongly” in a phone call Wednesday that he will respond to Ukraine’s weekend drone attack on Russian airfields.
The US president said in a social media post that “It was a good conversation, but not a conversation that will lead to immediate Peace.”
The call that lasted for an hour and 15 minutes was Trump’s first known with Putin since May 19. Trump said he and Putin also discussed Iran’s nuclear program.
