Kyiv, Ukraine - Ukrainian President Volodymyr Zelensky on Tuesday said Ukraine was favorable to a US-proposed truce on strikes against energy infrastructure endorsed by Russia but needed more "details" from Washington first.

Speaking after a call between US President Donald Trump and Russian President Vladimir Putin, Zelensky also warned in an online briefing that Putin wanted to "weaken" Ukraine and was "not ready to end this war".

"After we get the details from the US president, from the US side, we will give our answer," he told reporters of the energy truce.

"Our side will maintain it" as long as Moscow abides by it, he said, adding that the US should be "guarantors of control over the implementation".

Joke of the Day Joke of the Night for March 18, 2025: The best jokes to make you smile

"I think it would be right if we would have a conversation with President Trump and know the details of what the Russians offered the Americans or what the Americans offered the Russians," Zelensky said.

The Kremlin said Putin had agreed to a 30-day halt to strikes on Ukrainian energy infrastructure following the call with Trump but said that for a wide truce to work, Ukraine must not be allowed to rearm.

"They are not ready to end this war, and we can see that. They are not ready even for the first step, which is a ceasefire," Zelensky said, adding of Putin that "his whole game is to weaken" Ukraine.

Explosions rang out, and air raid sirens sounded over the Ukrainian capital, Kyiv, after the Trump-Putin call.

Kyiv authorities urged residents of the capital to take cover in shelters, citing the threat of a Russian aerial attack, while AFP reporters heard blasts sounding over the city.

Ukraine last week gave its backing to a full month-long ceasefire proposed by the US during bilateral talks in Saudi Arabia.

Zelensky also on Tuesday said that Ukrainian troops would continue fighting in Russia's Kursk region "as long as we need", following days of major Russian advances in the area.

Ukraine launched an offensive into the Kursk region last year in retaliation for an invasion that has seen Russian troops occupy swathes of southern and eastern Ukraine.