“I think it’s become clear that the U.S. doesn’t have any concessions that the Russian government wants for Paul, so I’m not really sure what the future holds,” David Whelan said.

The White House informed Whelan’s family of Griner’s release on Wednesday, David Whelan said, a day before Biden made the announcement to the public. In his remarks, Biden said his administration has “not forgotten about Paul Whelan,” and that it “was not a choice of which American we’re going to bring home.”

“Sadly, for totally illegitimate reasons, Russia is treating Paul’s case differently than Brittney’s,” Biden added. “And while we have not yet succeeded in securing Paul’s release, we are not giving up. We will never give up.”

David Whelan says “it’s not clear” what those reasons are, but it likely has to do with parity: “If they labeled Paul as a spy maybe they’re waiting until the U.S. government captures a spy and offer that as a trade,” he said.

Griner’s wife, Cherelle, also spoke about Whelan Thursday, saying his family was “in our hearts,” and that both she and Griner would “remain committed” to helping him — and all Americans — return home.

For now, David Whelan is focused on ensuring his brother’s safety.

“But really it’s a matter of helping Paul to survive until — and if — the U.S. government is able to find a concession that the Russian government wants,” he said. “It’s not magic. It’s just a ton of work.”