US President Donald Trump has “issued an ultimatum” to the two parties that they need to make progress on a lasting peace, otherwise the U.S. is walking away.

Axar.az reports White House senior adviser and assistant to the president Steve Witkoff told Breitbart News.

“The president has issued an ultimatum to both sides that without those direct talks and if they don’t occur quickly, then he believes the United States ought to step back from this conflict whatever that means and just not be involved,” Witkoff said. “This is something that we want to mediate. It’s not our war. We didn’t start the war, but we want to help to end it. The way that that happens is a ceasefire — everybody stops the violence, and we spend a bit of time together making sure we can deal with the major issues here and I think that we can.”

Major remaining issues to be hammered include details over the territory in Ukraine, a key nuclear power plant that is currently offline, and Ukrainian access to important waterways.

“I think the major issues here are the regions, the nuclear plant, it’s how the Ukrainians are able to use the Dnieper River and get out to the ocean,” Witkoff said. “There are things here that I don’t think are going to be difficult to solve if we get the parties to the table, they’re talking to each other, we’re narrowing issues between them, and then we’re coming up with compromises and creative solutions to address each of their concerns. We physically get that accomplished, and I think, hopefully, we’ll have some good news soon, but if we physically get that accomplished, we have, in my view, a strong chance to getting an end to this conflict.”

Asked in a follow-up question more about these remaining issues, Witkoff further explained there are about five regions in Ukraine currently disputed between the two sides — two under heavy Russian control and three under mixed Ukrainian control. He also said the offline nuclear power plant, Zaporizhzhia, is a “little bit of a crown jewel” because of how much electricity it can produce and is currently a “big part of this discussion.” In addition, waterways and how Ukraine accesses the Black Sea — which allows it to access the world’s oceans through its connections to the Mediterranean Sea — are important as well.

Please read the full interview here.