The family of a Wall Street Journal reporter detained in Russia has spoken out about the situation for the first time.

Evan Gershkovich’s mother told the Wall Street Journal that her family remains optimistic about his arrest in Russia. She said that the family will do whatever it takes to free him.

Gershkovich was arrested last month after being accused of trying to obtain classified information about a Russian military facility. He was charged with espionage.

Deputy Foreign Minister Sergei Ryabkov told the state news agency Tass that talks about a possible exchange could take place through a dedicated channel that Russian and U.S. security agencies established for such purposes.

However, he emphasized that Moscow would only negotiate a possible prisoner exchange after a trial.

Gershkovich, his employer and the United States government all deny he was involved in spying and have demanded his release.