Secretary of State Marco Rubio, national security adviser Mike Waltz and special envoy to the Middle East Steve Witkoff are headed to Saudi Arabia to initiate negotiations toward peace between Russia and Ukraine, two sources familiar with the matter told NBC News.

The timing of the travel was not specified, and it is unclear whether the trio have already departed.

The move comes just days after President Donald Trump said he spoke by phone with Russian President Vladimir Putin and Ukrainian President Volodymyr Zelenskyy about the prospect of beginning negotiations to end the war.

“We agreed to work together, very closely, including visiting each other’s Nations,” Trump wrote in a Truth Social post Wednesday after the call. “We have also agreed to have our respective teams start negotiations immediately.”

Senior Trump administration officials, including Vice President JD Vance, Rubio and U.S. special envoy to Ukraine Keith Kellogg, have been huddling in Germany this weekend for the Munich Security Conference, a forum for international security policy where the Russia-Ukraine war remains a critical topic of discussion.

Rubio spoke by phone with Russian Foreign Minister Sergey Lavrov on Saturday. Their discussion included the war in Ukraine and other topics, according to readouts of the call from both countries.

During a speech at the security conference Saturday, Zelenskyy said Ukraine must be involved with any negotiations to end the war.

“Ukraine will never accept deals made behind our backs,” he said. “No decisions about Ukraine without Ukraine, no decisions about Europe without Europe.”

On Saturday, Kellogg defended the prospect of engaging with Putin in an effort to achieve peace between Russia and Ukraine, saying in Munich, “Whether you like it or not, you have to talk to adversaries.”

“As a great secretary of defense, Gen. Mattis, once said: I may not like this son of a b—-, but I got to talk to him,” he added.

Kellogg also said at the conference Saturday that Western leaders need to do more to enforce sanctions against Russia, adding that negotiations about ending the war could focus on Russia’s willingness to cede territory and targeting Putin’s oil revenue.

But some members of the administration have seemed reluctant in recent days to specify any particular concessions from Russia ahead of potential negotiations.

Asked Thursday what Russia should give up in order to reach a deal with Ukraine, Trump declined to name specifics.

“As far as the negotiation, it’s too early to say what’s going to happen. Maybe Russia will give up a lot, maybe they won’t, and it’s all dependent on what is going to happen,” Trump said during a news conference alongside Indian Prime Minister Narendra Modi.

Defense Secretary Pete Hegseth, who has signaled the U.S. would be opposed to Ukraine joining NATO as part of a negotiated peace, indicated that the U.S. is likely to support negotiations in which Ukraine cedes territory that’s already been seized by the Kremlin.

“We want, like you, a sovereign and prosperous Ukraine. But we must start by recognizing that returning to Ukraine’s pre-2014 borders is an unrealistic objective,” Hegseth said in a speech during a trip to NATO’s headquarters in Brussels on Wednesday.