Ukraine's Defence Minister Rustem Umerov said talks with the US delegation in Saudi Arabia on Sunday were "constructive and meaningful" and focused on discussing the energy sector.

"We discussed key issues, particularly the energy sector," Umerov said in a post on social media.

Umerov headed the Ukrainian delegation for the talks that were part of a diplomatic push by US President Donald Trump to end three years of war with Russia.

US special envoy Steve Witkoff expressed earlier optimism ahead of high-stakes talks in Saudi Arabia to end the war in Ukraine and said he believed Russian President Vladimir Putin wanted to end the three-year-old conflict.

"I feel that he wants peace," Witkoff told Fox News on Sunday.

A US delegation is held the talks in Saudi Arabia with Ukrainian officials on a possible partial ceasefire between Ukraine and Russia. US and Russian officials will also hold talks on Monday, also in Riyadh.

"I think that you're going to see in Saudi Arabia on Monday some real progress, particularly as it affects a Black Sea ceasefire on ships between both countries. And from that, you'll naturally gravitate into a full-on shooting ceasefire," Witkoff said.

Putin agreed last week to stop attacking Ukrainian energy facilities temporarily but declined to endorse a full 30-day ceasefire that Trump hoped would be the first step toward a permanent peace deal. Ukraine accepted Trump's 30-day proposal.