A US journalist working for The Wall Street Journal has been arrested in Russia on charges of spying for Washington, Russia's FSB security services confirmed on Thursday.

The FSB security services pointed out that they had "halted the illegal activities of US citizen Evan Gershkovich," specifying that The Wall Street Journal reporter was "suspected of spying in the interests of the American government."

Their statement confirmed that Gershkovich, 31, was working with press accreditation issued by the Russian Foreign Ministry.

But the statement said he had been detained for gathering information "on an enterprise of the Russian military-industrial complex."

"The foreigner was detained in Yekaterinburg while attempting to obtain classified information," the FSB said, referring to a city in central Russia 1,800 kilometers (1,100 miles) east of Moscow.

Before joining The Wall Street Journal Gershkovich worked for AFP in Moscow.

On her part, Russian Foreign Ministry Spokesperson Maria Zakharova wrote on her Telegram channel that Gershkovich was not engaged in any journalistic work.

"What an employee of the US paper The Wall Street Journal was doing in Yekaterinburg has nothing to do with journalism," Zakharova said.

"Unfortunately, this is not the first time that the status of a 'foreign correspondent', a journalistic visa and accreditation are used by foreigners in our country to cover up activities that are not related to journalism," she noted.

According to the Russian spokesperson, Gershkovich "is not the first well-known Westerner who got caught in action."

Kremlin Spokesperson Dmitry Peskov later said Gershkovich was caught red-handed.

"The only thing I can say is that, as far as we know, he was caught red-handed," Peskov told reporters when asked if Moscow will cooperate with the US intelligence services on the matter.

Commenting on a possible response measure by the US, the official expressed the hope that there will be no reaction.

"We hope that this will not happen and this should not happen because once again I repeat it is not about suspicions, it is about the fact that he was caught red-handed," he said.

Additionally, he said that employees of the WSJ Moscow bureau can continue to work if they are accredited.

In response to its reporter's detention, The Wall Street Journal said Thursday it "vehemently denies" the Russian allegations.

"The Wall Street Journal vehemently denies the allegations from the FSB and seeks the immediate release of our trusted and dedicated reporter, Evan Gershkovich," the newspaper said in a statement. "We stand in solidarity with Evan and his family."