Ukraine on Saturday was seriously considering a revised American proposal for its vast natural resources that contains virtually the same provisions that Kyiv previously rejected as too onerous, according to Ukrainian officials and a draft of the deal.

In fact, some of the terms appear even tougher than in a previous draft. The latest proposal comes after a week in which President Volodymyr Zelensky of Ukraine resisted signing the earlier version in a public dispute with President Trump.

The proposed agreement would significantly shift onto a mercantile footing the United States’ three-year alliance with Ukraine in the largest war in Europe since World War II. The conflict to date has largely been seen as a struggle to secure Ukraine and the European continent from an authoritarian threat from Russia.

The Trump administration’s terms could also strip Ukraine of some funds that are now mostly invested in the country’s military and defense industry, and that could help rebuild the country once the war is over.

The terms of the new proposal, which is dated Feb. 21 and was reviewed by The New York Times, call for Ukraine to relinquish to the United States half of its revenues from natural resources, including minerals, gas and oil, as well as earnings from ports and other infrastructure. A similar demand was made in a previous version of the deal, dated Feb. 14 and reviewed by The Times.

Ukraine had been floating the prospect of a partnership with the United States on its valuable natural resources as a way to persuade Mr. Trump to provide additional support for its war effort. Mr. Zelensky had also been seeking security guarantees for Ukraine, a condition that was absent in the first draft agreement presented to him last week, prompting him to decline to sign the deal.