Sen. Roy Blunt wants Secretary of State John Kerry to provide "a detailed accounting" of the $400 million cash payment to Iran that was linked to the release of American hostages held there.

Blunt, R-Mo., who serves on the Senate Intelligence panel as well as the Appropriations subcommittee that oversees the State Department, said that even though the Obama administration has denied the money was paid as a ransom for the hostages, "the facts continue to suggest otherwise."

Blunt then demanded Kerry provide the quarterly statements from a Foreign Military Sales account that the Obama administration said was the source of $400 million payment.

Iran had used the fund to buy military equipment before 1979, when the United States ended diplomatic relations with the country, a major sponsor of terrorism in region.

Blunt joins a growing chorus of congressional lawmakers seeking more details about the money, which was flown to Iran in January just as four American hostages were released.

Blunt said he wants to determine whether taxpayer money was ultimately used.

U.S. taxpayers, Blunt said, have already paid to Iran the $1.3 billion in interest on the account.

"I have serious concerns that the $400 million you provided in hard currency to a terrorist regime will also come out of U.S. taxpayers' pockets," Blunt said.

Last week, State Department spokesman John Kirby acknowledged that the money was used as "leverage" to ensure the hostages were allowed to leave the country, but would not call it ransom.