(JTA) — The Trump administration is considering an offer from Republican mega-donor Sheldon Adelson to pay for at least part of a new U.S. embassy in Jerusalem, four US officials told The Associated Press.

Lawyers at the State Department are looking into the legality of accepting private donations to cover some or all of the embassy costs, the administration officials told the news agency, which published an article on the reported plan Friday.

The discussions are occurring, the report said, as the new embassy clears its final bureaucratic hurdles. On Thursday, Secretary of State Rex Tillerson ended weeks of delay by signing off on a security plan for moving the embassy from Tel Aviv to the holy city, according to the officials, who weren’t authorized to discuss the issue publicly and demanded anonymity.

In one possible scenario, the administration would solicit contributions not only from Adelson but potentially from other donors in the evangelical and American Jewish communities, too. One official said Adelson, a Las Vegas casino magnate and staunch supporter of Israel, had offered to pay the difference between the total cost, expected to run into the hundreds of millions of dollars, and what the administration is able to raise.

Under any circumstance, letting private citizens cover the costs of an official government building would mark a significant departure from historical U.S. practice, according to The Associated Press.

It’s not clear if there are any precedents, nor whether government lawyers would give the green light to accept Adelson’s or anyone else’s donations for the embassy.

Adelson’s unconventional offer was made around the time Trump announced in December he would move the embassy to the disputed city of Jerusalem. It would address the president’s stated distaste for shelling out large sums for overseas diplomatic facilities. Although Trump has promoted the Jerusalem move as fulfilling a key campaign promise, he also was outspoken last month in blasting the $1 billion price tag for a new embassy in London.

Since Trump’s announcement, his administration has been sifting through options for fast-tracking the Israel embassy’s relocation. Last month, Vice President Mike Pence announced during a visit to Israel that the embassy would move by the end of 2019 — possibly earlier.

Ambassador David Friedman, who lobbied for Trump’s decision to recognize Jerusalem as Israel’s capital, has advocated moving the embassy as soon as possible.

The United States has looked at several possible sites. The most likely plan involves a phased approach to opening the embassy in Jerusalem’s Arnona neighborhood at an existing US facility that handles consular affairs like passports and visas. The United States could initially retrofit a small suite of offices in that facility to accommodate Friedman and one or two top aides such as his chief of staff.

It’s unclear how much of the cost Adelson might be willing to cover.