ASPEN, Colo. — Roger Carstens, the special presidential envoy for hostage affairs, pushed back on Wednesday on those who have argued that the U.S.’ $6 billion hostage deal with Iran last year has incentivized further hostage-taking.

“The numbers don’t back that up,” Carstens said on Wednesday at the Aspen Security Forum. Carstens said that “common sense dictates” that the U.S. making deals would prompt malign actors to take more American hostages — “but strangely it’s absolutely the other way around.”

He said that the number of cases before his office has gone down by around half from its highest level, highlighting efforts to prevent and deter hostage-taking by both the U.S. and multilateral partners.

Carstens, who was first appointed by former President Donald Trump and was kept in his position by President Joe Biden, also emphasized that deals like the one that freed the U.S. hostages from Iran last year are the only lifeline to freedom for them and their families.

“If you don’t make these deals, people just don’t come home,” Carstens said. “So you’ve got to picture people like your son, your daughter, your wife, your husband, your grandfather — they get arrested, they’re thrown into jail, and the United States of America just says, ‘Well, we don’t make those deals.’ There’s no other alternative.”

He acknowledged that such deals are “probably not going to be pleasing to everyone but we’re committed to finding a way to get it done.”

Carstens described the negotiations with Iran as particularly “excruciating” and among the most difficult he’s been involved in, in part because “there’s always the chance that your hostage negotiation is going to jump into the broader policy discussion. And that can be good or bad, but you lack some control there.”

The hostage deal with Iran also involved the release of a number of Iranian prisoners held in the U.S. Carstens said officials carefully examine each case and the potential implications of releasing those that adversaries request the U.S. release. He added that he’s not aware of any cases where prisoners freed from the U.S. as part of such deals have returned to malign activities.

“Sometimes the decision is going to be no, and other times the president is going to assume the responsibility, make that decision, and then we’ll execute,” Carstens said. “But under President Biden, we brought back 47 Americans, and a lot of that comes down to the president making some pretty tough decisions on behalf of bringing these Americans home.”

While the case of the eight American hostages being held in Gaza falls partly within Carstens’ remit, he said that the case is being handled by the highest levels of the U.S. government, and that he’s not the lead negotiator at the table.

“There’s a whole-of-government effort to negotiate for the release,” Carstens said. “With Gaza, our nation definitely [has] a foot on the gas and the car is moving forward.”

He said that the negotiation is “in motion” but also that circumstances are changing rapidly. “It’s best to just let the people that are forward do what they need to do and not talk about it in public.”

Carstens added that the U.S. is attempting to place an observer at Wall Street Journal reporter Evan Gershkovich’s next hearing in Russia — where he’s been imprisoned for more than a year — scheduled for Thursday. 

“I know Evan and Paul [Whelan] will come home to the United States and step onto U.S. soil, I just don’t know when,” he said.

The hostage envoy also described the resolution of last year’s Iran hostage case as particularly rewarding. He said being on the tarmac seeing Siamak Namazi, who had been detained in Iran since 2015, reunite with his wife was an especially moving experience.

“It’s so intimate and personal to watch a husband and a wife, who have not seen each other, connect, that you really feel like you shouldn’t watch it,” Carstens said. “But you’re also stuck and captivated by this very human moment. So you watch it, you tear up … it makes everything worth it. I just wish we had more of those moments.”