Putin called the summit in Geneva "constructive" and without "hostility."
U.S. President Joe Biden held a high-stakes summit with Russian President Vladimir Putin on Wednesday at what the leaders agree is a "low point" in the U.S.-Russia relationship.
The two men faced off inside an 18th-century Swiss villa, situated alongside a lake in the middle of Geneva's Parc de la Grange. The fifth American president to sit down with Putin, Biden has spoken with him and met him before, in 2016.
Having called Putin a "killer" and saying he's told him before he has no "soul," Biden told ABC News Chief White House Correspondent Cecilia Vega on Monday that he also recalled the Russian leader as being "bright" and "tough."
"And I have found that he is a -- as they say, when you used to play ball -- a worthy adversary," Biden said.
Photos ahead of high-stake summit between Biden and Putin
Putin indicated on Friday that he'd be willing to talk about a potential "prisoner swap" between two U.S. Marine veterans, Trevor Reed and Paul Whelan, for Russians being held in the U.S.
Russian officials have indicated they would like to trade Reed and Whelan for two Russians held in the U.S.: Viktor Bout -- one of the world's most notorious arms dealers and dubbed "the Merchant of Death" — and also Konstantin Yaroshenko, a pilot currently serving a lengthy jail sentence for a drug smuggling conviction.
David Whelan told ABC News Live Prime anchor Linsey Davis on Tuesday that his brother, who is manufacturing clothes in a Russian labor camp, is a hostage and that it's difficult to know when that might come to an end.
"I'm always hopeful that he'll be released, but I don't have any idea what the timeline might be," David Whelan said. "The Biden administration has been very outspoken about Paul's case and we've appreciated that as a family. It's given us hope and it's given him hope."
"But he's still a hostage and there's no evidence yet that the Russians are willing to exchange in any exchange for him," David Whelan continued. "They said last week -- the Russian government did — that they would not consider Paul for exchange."
Whelan's family released an audio message from him on Monday recorded from the prison camp in central Russia where he is held. In it, he appealed to Biden to help free him.
"Please bring me home to my family and my dog Flora where I belong. Thank you, Mr. President, for your commitment to returning me home and bringing this deplorable hostage situation to an expedient conclusion," Whelan said in the recording that his family said was made on May 30.
-ABC News' Haley Yamada and Patrick Reevell
Ahead of Wednesday's summit in Switzerland, both leaders agreed that it is a "low point" between the U.S. and Russia relationship
Biden to hold high-stakes summit with Putin on Wednesday
Ahead of the summit, ABC News Chief Global Affairs Correspondent Martha Raddatz said Biden needs to walk a fine line in an effort not to alienate Putin.
"He wants the relationship to be better — the U.S.-Russia relationship — to be better than it has been," Raddatz said on ABC News Live Prime Tuesday. "And they both agree that it's at one of the lowest points in history."
"So, President Biden will have to give his grievances to Putin, telling him what he wants to do — and yet, we even heard a bit of that today, a little flattery, a little, you know, he is a 'tough guy,' he is a 'bright guy,' President Putin, and he is a 'worthy adversary,'" Raddatz continued. "That is diplomacy 101."
In a separate interview with ABC News' Linsey Davis, Masha Gessen, a staff writer at the New Yorker and author of "Surviving Autocracy," agreed that "Russian-American relations are at an all time low."
"Biden is faced with an incredibly difficult challenge," Gessen added.
Watch the interview:
