The United States is giving $30 million to a controversial humanitarian group delivering aid in war-torn Gaza despite concern among some U.S. officials about the month-old operation and the killing of Palestinians near food distribution sites, according to four sources and a document.

Washington has long backed the Gaza Humanitarian Foundation diplomatically, but this is the first known U.S. government financial contribution to the organization, which uses private U.S. military and logistics firms to transport aid into the Palestinian enclave for distribution at so-called secure sites.

A document showed that the $30 million U.S. Agency for International Development grant to GHF was authorized on Friday under a "priority directive" from the White House and State Department. The document showed an initial $7 million disbursement had been made.