Former U.S. Marine Paul Whelan, who was detained and accused of espionage, holds a sign as he stands inside a defendants’ cage during his verdict hearing in Moscow, Russia June 15, 2020.Maxim Shemetov | ReutersPresident Joe Biden said he and Russian President Vladimir Putin discussed the fate of U.S. citizens detained in Russia during the leaders’ summit Wednesday in Geneva.”To the family of the detained Americans, we discussed it, and we are going to follow through with that discussion. I am not going to walk away on that,” Biden said at the conclusion of a press conference.During his press conference after the meeting, Putin gave no details about a potential prisoner swap but said that the discussions would continue.Secretary of State Antony Blinken had said that potential prisoner swaps would be on the table for the Putin-Biden discussion. Blinken and other top officials joined Biden for meetings with their Russian counterparts.In May, Blinken called on Moscow to release former U.S. Marines Paul Whelan and Trevor Reed, who are serving 16-year and 9-year prison sentences, respectively, according to a State Department readout of a conversation with Russian Foreign Minister Sergey Lavrov.Reed was sentenced to nine years in a Russian prison last year after he was convicted of assaulting a police officer during a night out in Moscow. Whelan was arrested in 2018 on charges of acting as a spy for the United States. At the time he was arrested, Whelan was visiting Russia to attend a wedding, according to his brother David Whelan. Both Whelan and Reed deny the charges against them.Former U.S. Marine Trevor Reed, who was detained in 2019 and accused of assaulting police officers, stands inside a defendants’ cage during a court hearing in Moscow, Russia March 11, 2020.Tatyana Makeyeva | ReutersThe U.S. ambassador to Russia, John Sullivan, called the evidence against Reed “flimsy.” “If this case had been brought in a U.S. court, not only would it have been thrown out, but the prosecutors would be investigated for bringing it forward in the first place,” Sullivan told NBC News. In the days leading up to the summit, Reed’s parents publicly appealed to Biden to seek their son’s release. They’ve also said they wouldn’t object to a prisoner swap between Moscow and Washington if it meant the return of their son. “We don’t care how he comes home, if they want to exchange Trevor for some criminals that, you know, are low-level criminals or whatever,” Trevor’s father, Joey Reed, said on NBC’s “TODAY” show on Monday.”We’re fine with that. We want our son home,” said Trevor’s mother, Paula Reed.David Whelan, however, has expressed concerns about the idea of a prisoner swap.CNBC PoliticsRead more of CNBC’s politics coverage:”He is innocent, he was wrongly accused. We would rather see the door come open and him come out rather than some sort of negotiated release of Russian convicts,” Whelan said Monday on “TODAY.”Putin, who was first to address the press after the bilateral meeting, said that talks with Biden were “very productive” and “there has been no hostility” between the two.In a separate press conference, Biden described the talks as “good, positive” and reiterated that he was hopeful the two leaders could work together on common interests.