The White House secured the release of five Americans imprisoned in Iran in exchange for several Iranian nationals imprisoned in the United States as well as the release of nearly $6 billion in frozen Iranian oil funds.

“The move by Iran of the American hostages from Evin Prison to house arrest is an important development,” Jared Genser, a lawyer representing one of the Americans released in the deal, told the New York Times.

“While I hope this will be the first step to their ultimate release, this is at best the beginning of the end and nothing more,” the attorney added. “But there are simply no guarantees about what happens from here.”