The Obama administration is attempting to explain a $400 million payout to Iran that occurred during a hostage crisis earlier this year. Republicans including House Speaker Paul Ryan are demanding an explanation, some saying that the cash could go toward funding terrorist groups.

The Washington Examiner reported:

The Obama administration on Wednesday was defending the transaction as a move to pay Iran back the money it gave the U.S. in 1979 as part of an arms deal that never went through after the Shah of Iran was overthrown. But Republicans were asking questions about the timing of the payment and whether it’s related to the release of four Americans who were detained in Iran, but were released when the cash was sent.

Some were also saying sending cash will only make it easier for Iran to fund terrorist organizations, and harder for the U.S. to trace those payments.