US President Donald Trump and Russian President Vladimir Putin held a discussion about Ukraine by phone on Tuesday in which the two leaders agreed to halt attacks on energy facilities and infrastructure to achieve a ceasefire.

The White House released a statement revealing details of the talks on Tuesday.

It said the two leaders "agreed that the movement to peace will begin with an energy and infrastructure ceasefire."

The statement also said Washington and Moscow will immediately begin negotiations on the implementation of "a maritime ceasefire in the Black Sea, full ceasefire and permanent peace" as well.

But Putin did not accept a 30-day ceasefire proposed by the United States, saying it had problems. Ukraine earlier announced that it would accept the proposal.

The Russian presidential office said Putin responded positively to Trump's proposal that both Russia and Ukraine stop attacking energy-related facilities for a period of 30 days. The office said Putin gave the Russian military the appropriate command.

The office said the US and Russia also agreed to set up Russian and American expert groups as efforts to settle the Russian-Ukrainian conflict.

But the office said the key condition for preventing the conflict from escalating is the complete cessation of foreign military assistance and the provision of intelligence to Kyiv.

In addition, the office said the need to address the root causes of the crisis and Russia's legitimate security interests should be taken into account.

The office said one reason for rejecting the 30-day ceasefire is that it may allow Ukraine to rebuild its military.

There are discrepancies in the announcements by the US and Russia. Russia said it would halt attacks on energy-related facilities for 30 days. Meanwhile, the US cites energy facilities, infrastructure and others, but makes no mention of duration.