Moscow, Russia - Russian President Vladimir Putin ordered a 30-day halt to strikes on Ukrainian energy infrastructure following a call with US counterpart Donald Trump, the Kremlin said on Tuesday.

But Putin said that, for a wider truce to work, Ukraine must not be allowed to rearm and must halt mandatory mobilization.

The Kremlin said the two leaders had a "detailed and frank exchange of views".

Putin outlined a number of conditions for a possible ceasefire, including "the need to halt both forced mobilization in Ukraine and the rearmament of the Ukrainian armed forces," the Kremlin said.

Donald Trump Trump administration threatens to slash federal funding for New York City's MTA

He also questioned how such a ceasefire could be monitored.

Trump proposed a 30-day halt on strikes on energy targets and "Vladimir Putin responded positively and immediately gave the Russian military a corresponding command", the statement added.

Russia and Ukraine will also swap 175 prisoners each on Wednesday following the call, the Kremlin said.

Putin said the Ukraine conflict could only be resolved long-term if the West halted military and intelligence support for Ukraine.

"The key condition for preventing an escalation of the conflict and working towards its resolution through political and diplomatic means should be a complete cessation of foreign military assistance and the provision of intelligence to Kyiv," the Kremlin said.