The Wall Street Journal on Saturday demanded the immediate release of its Moscow correspondent Ivan Gershkovich, who was arrested by Russia's Federal Security Service (FSB) on espionage charges, while the Kremlin tried to reassure foreign reporters that they could continue to work in Russia without fear as long as they "do not use their jobs as cover to perform espionage missions."

"Ivan's case is a grave affront to a free press and should outrage all free individuals and governments around the world," the newspaper said in a statement posted on Twitter.

Statement from @WSJ on reporter Evan Gershkovich #IStandWithEvan

— WSJ Communications (@WSJPR) April 1, 2023

Russian presidential spokesman Dmitry Peskov said on Friday that foreign correspondents in Russia should not be afraid if they are performing their declared duties and not using their job as a cover to perform espionage missions.

"All journalists who have a valid accreditation here, I mean foreign journalists, can continue their journalistic activity and continue it already in the country; they face no restrictions and they work well," he told a news conference.

Peskov noted that Ivan Gershkovich was conducting espionage "under the cover" of the press, adding that an investigation into his case was ongoing.

The spokesman also said there was "no reason" to expel all Russian journalists from Western countries in response to Gershkovich's arrest.

Russia has not published any evidence to support the charges, which the newspaper denied, and this is the first such case against a U.S. reporter since the end of the Cold War.

On Friday, US President Joe Biden called on Russia to release the Wall Street Journal reporter.

The arrest of Gershkovich, 31, a certified correspondent in the city of Yekaterinburg, Russia, 6 years ago, on charges of "spying for the US government," according to the Russian Federal Security Service, charges that the US administration said were false.

In his latest report from Moscow, published earlier last week, Gershkovich focused on the slowing Russian economy amid Western sanctions imposed when Russian forces launched their operation in Ukraine last year.

A Moscow court ordered Gershkovich's detention until at least 29 May in preparation for his trial.