Russian President Vladimir Putin told US President Donald Trump in a phone call Wednesday that Moscow was obligated to respond to Ukraine’s weekend drone attack, Trump said, setting up a potential escalation in the conflict just as the US president hopes to broker an end to the war, writes CNN.

The leaders’ conversation was their second time speaking in a matter of weeks. Trump, who announced the call afterward in a post on Truth Social, made no mention of applying pressure on the Russian leader to agree to a ceasefire, or to calibrate his reprisal for Ukraine’s audacious drone attack on Russian airfields over the weekend.

Instead, Trump acknowledged the 75-minute conversation would not yield an immediate end to the war in Ukraine.

“We discussed the attack on Russia’s docked airplanes, by Ukraine, and also various other attacks that have been taking place by both sides”, Trump wrote in a post on Truth Social. “It was a good conversation, but not a conversation that will lead to immediate Peace. President Putin did say, and very strongly, that he will have to respond to the recent attack on the airfields”.

In comments on the Trump-Putin call, Kremlin aide Yury Ushakov said the topic of Ukraine’s raid on the airfields “was also touched upon.” But Ushakov did not say if Putin said he would respond to those attacks.