LONDON (Reuters) -The U.S. fund overseeing U.S. President Donald Trump's critical minerals deal with Ukraine said on Friday it had appointed advisory firm Alvarez & Marsal to help it identify and size up potential opportunities.

Ukraine and the U.S. in April signed a deal, heavily promoted by Trump, that gave the United States preferential access to new Ukrainian minerals projects in exchange for investment.

The U.S. government's International Development Finance Corporation (DFC) was then charged with overseeing a newly created U.S.-Ukraine Reconstruction Investment Fund. It injected $75 million into the fund to begin financing critical minerals, energy, and infrastructure projects.

Conor Coleman, DFC's Head of Investments and Chief of Staff, said on Friday it had appointed financial advisory firm Alvarez & Marsal "to support the Fund's investment processes" and help in conducting due diligence and financial analysis.

DFC sent a team to Ukraine in September to start identifying potential projects. Ukraine's Economy Minister Oleksiy Sobolev said at the time the government wanted to identify at least three pilot investment projects within the next 18 months.

The U.S. has been Ukraine's single largest military donor as it battles Russian forces. Since his return to the White House this year, Trump has argued the U.S. should get something back for its aid to Kyiv.

Half the revenues the Ukrainian government earns from new mineral extraction under the minerals deal are earmarked to go to the joint investment fund, with profits split between Kyiv and Washington.