Ukraine and the United States signed a memorandum of understanding late on Thursday as a “step toward a joint economic partnership agreement,” according to Ukraine’s economy minister, bringing both sides closer to a minerals deal that has gone through multiple, contentious rounds of negotiations.

The agreement was thin on details. While it referred to the creation of a fund that would invest in reconstruction in Ukraine — which has been devastated by the war Russia has waged since a full-scale invasion in 2022 — it did not specify the source of such revenue.

There was no immediate comment from the White House. But the Ukrainian minister, Yulia Svyrydenko, who is also deputy prime minister, announced the agreement in a post on Facebook, after signing it on a video call with the U.S. Treasury secretary, Scott Bessent, who was in Washington. Ms. Svyrydenko said the agreement would “benefit both our peoples.”

Mr. Bessent, in his own comments on Thursday afternoon, did not mention he had signed the memorandum but said he expected a full deal next week.

Earlier drafts of a minerals deal had swiveled between what critics called a brazen extortion of Ukraine by the Trump administration and versions that included points sought by Ukraine, such as references to U.S. support for post-settlement security guarantees.