The Kremlin said on Monday that contacts had taken place with the United States over a possible prisoner exchange involving Wall Street Journal reporter Evan Gershkovich but that they should remain far from the media.

Kremlin spokesman Dmitry Peskov quoted President Vladimir Putin's remarks earlier this month at a meeting with senior international news agency editors. Putin said then that Russia and the United States were in contact on the issue.

"I want to remind you again of the president's conversation with the heads of information agencies in St. Petersburg - he confirmed that there are such contacts," Peskov said.

"They go on but should continue to be conducted in complete silence... Therefore, no announcements, statements, or information on this matter can be provided."

When asked why the espionage trial of Gershkovich was to be held behind closed doors, Peskov said that he was unable to comment on such matters as it was a decision made by the court.

"This is a court decision. We cannot comment on it," Peskov said.

Gershkovich, 32, was detained by the Federal Security Service (FSB) on March 29, 2023, in a steak house in the Urals city of Yekaterinburg, 1,400 km (900 miles) east of Moscow, on charges of espionage that carry up to 20 years in prison.

The first American journalist to be detained on spy charges in Russia since the Cold War more than three decades ago, Gershkovich has repeatedly denied the charges.