Vladimir Putin, the president of Russia, stated on Friday that there could be more prisoner exchanges between the US and Russia and that intelligence service communications will continue.

In the most publicized prisoner exchange between the two nations in recent memory, the United States released Russian arms dealer Viktor Bout in exchange for American basketball player Brittney Griner while Putin spoke at a press conference in Bishkek, Kyrgyzstan.

Putin was asked if other exchanges were possible.

“Yes, anything is possible,” he replied. “Contacts continue. In fact, they have never stopped … A compromise was found, we do not reject continuing this work in the future.”

Russia continues to hold Paul Whelan, a U.S. Marine Corps veteran who was convicted of espionage in 2020 in a trial that U.S. diplomats said had been unfair and opaque.

The Russian news agency Interfax on Thursday reported that talks between Washington and Moscow on freeing Whelan were continuing, citing Whelan’s lawyer.