AP — President Donald Trump is railing against law enforcement and lawmakers — this time over an Obama-era payment to Iran.

Trump says in a tweet that he’s “never gotten over the fact that Obama was able to send $1.7 Billion Dollars in CASH to Iran and nobody in Congress, the FBI or Justice called for an investigation!”

The Obama administration transferred the money to Iran in 2016, using non-U.S. currency. The administration said it was the settlement of a decades-old arbitration claim between the countries. An initial payment was delivered the same day Tehran agreed to release four American prisoners.

The Obama administration eventually acknowledged the cash was used as leverage until the Americans were allowed to leave Iran. Congressional Republicans decried the payment as ransom, which the Obama administration denied.