Derek Maltz, who oversaw the Drug Enforcement Administration’s investigation of Viktor Bout, told ABC News he’s “very disgusted” that Bout, a convicted Russian arms dealer, was traded for Brittney Griner.

“It’s really upsetting to me,” he said.

In 2008, Maltz was the special agent in charge of the DEA’s special operations division whose agents took down Bout in a sting operation in Thailand.

“DEA was asked to help take this guy down because he was such a national security threat,” Maltz said.

In November 2007, Bout agreed to sell DEA informants posing as rebels in Colombia millions of dollars in weapons.

“Bout was ready to sell a weapons arsenal that would be the envy of any small country,” Maltz said.

Maltz called this “a great day for Brittney Griner and for America,” but added that he thinks the exchange for Bout will make Americans traveling abroad less safe.

“To make that exchange, all Americans are at greater risk with international travel,” Maltz said, fearing it would promote taking American citizens captive.

-ABC News’ Aaron Katersky

Brittney Griner is “in an extremely upbeat mood” and is “all smiles,” according to a senior Biden administration official.

The athlete is “in good health” and “is being offered a wide range of support options following her time wrongfully detained,” the official added.

The agreement to secure her release was reached in “recent days,” the official said.

“Through multiple, multiple engagements, the Russians made clear that the only route to securing Britney's return was a release of a Russian national, Viktor Bout,” the official said. “In the last 48 hours, as this had all come together, Brittney was moved from the penal colony where she was being held to Moscow, and this morning, she was brought to the United Arab Emirates, where she was met by U.S. officials.”

-ABC News’ Ben Gittleson

New photos released by Jill Biden's office show the first lady hugging Brittney Griner's wife, Cherelle Griner, at the White House Thursday morning.

"Brittney is coming home," the first lady wrote.

House Speaker Nancy Pelosi said in a statement, “Congress and the Country are overjoyed to learn that, thanks to the committed and focused leadership of President Biden, Brittney Griner is finally free. Today, our hearts are with her dear wife, Cherelle, and the entire Griner family as their beloved Brittney is safely on her way back to America and will be home for the holidays."

“For nearly ten long months, Brittney Griner suffered unthinkable trauma as she was wrongfully imprisoned by the Russian government," Pelosi said. "Putin’s cruelty against Brittney – and his monstrous actions against Ukraine – are staggering reminders of his brazen contempt for human rights, human dignity and the rule of law."