WASHINGTON — Sheldon G. Adelson, one of the most hawkish supporters of the Israeli regime among American Jews, has offered to help fund the construction of a new US Embassy in occupied Jerusalem, according to the State Department, which on Friday said it was reviewing whether it could legally accept the donation.

The total price tag to build the new embassy to replace the current one in Tel Aviv is estimated at $500 million, according to one former State Department official. While private donors have previously paid for renovations to American ambassadors’ overseas residences, Adelson’s contribution would be likely to far surpass those gifts — and could further strain American diplomacy in the Middle East.

Before the embassy is built, the Trump administration plans to open a temporary one in occupied Jerusalem. On Friday, it said that it was accelerating the projected opening in time to mark the 70th anniversary of the creation of the State of Israel on May 14.

If the administration accepts Adelson’s offer for the permanent embassy, even some of his allies expressed concern that it could be seen as a well-heeled financial contributor effectively privatising — and politicising — US foreign policy.

Adelson, who has been a vocal supporter of the contentious plan to move the embassy, is not merely a philanthropist; he is one of the most prominent players in Israeli-American relations. He is a conservative force in US politics, a donor to President Donald Trump, a longtime patron of Prime Minister Benjamin Netanyahu and the owner of Israel’s largest-circulated daily newspaper.

“I’m concerned that people will think that this is being done because of a group of people — evangelicals and Jews — who care about it and not because it’s the US government that cares about it,” said Morton A. Klein, who runs a non-profit group called the Zionist Organisation of America that is funded partly by Adelson. “It should be crystal-clear that this is the US government making the decision to move it.”

Through a representative, Adelson declined to comment Friday. His offer of a donation was first reported by The Associated Press.