The United States on Thursday expressed deep concern over Russia's arrest of Wall Street Journal reporter Ivan Gershkovich on espionage charges, in the first such incident since the Cold War, and the White House called on American citizens to leave Russia immediately.

EU foreign policy chief Josep Borrell also condemned the journalist's arrest, criticizing what he called Moscow's "systematic contempt" for press freedom.

In a statement, US Secretary of State Antony Blinken expressed concern about the journalist's arrest, adding that he was in contact with the Wall Street Journal.

"When a U.S. citizen is detained abroad, we immediately seek to contact the consulate and seek to provide all appropriate support," he said.

"We condemn in the strongest possible terms the continued attempts of the Russian presidency (the Kremlin) to intimidate, suppress and punish journalists and civil society voices," he said.

White House spokeswoman Karine Jean-Pierre said in another statement, "We are deeply concerned by troubling reports of the arrest of U.S. citizen Ivan Gershkovich in Russia," noting that the White House and State Department officials were in contact with The Wall Street Journal and the family of the detained journalist.

"The Foreign Ministry has been in direct contact with the Russian government on this matter, including actively working to secure Mr. Gershkovich's access to the consulate," she said.

"The targeting of U.S. citizens by the Russian government is unacceptable, and we strongly condemn the arrest of Mr. Gershkovich," the spokeswoman said.

The statement condemned "the Russian government's continued targeting and repression of journalists and press freedom."

It is noteworthy that the arrested journalist Ivan Gershkovich, 31, worked in Russia for 6 years, and was arrested in the Russian city of Yekaterinburg, on charges of "spying for the US government," according to the Russian Federal Security Service (FBS).

He was accused of operating under U.S. instructions to obtain classified information related to a Russian military-industrial complex.

The Wall Street Journal "vehemently" denied the spying allegations against Gershkovich and called for his "immediate release," while Russian Foreign Ministry spokeswoman Maria Zakharova said Gershkovich was using his credentials as a cover for "activities unrelated to journalism."

The arrest comes amid growing tensions between the West and Moscow, over its war on Ukraine, which it launched on February 24, 2022.

The Associated Press reported that Gershkovich faces up to 20 years in prison if convicted of espionage, and quoted a senior Russian official as saying it was too early to talk about any prisoner swap deal even though Moscow and Washington had struck deals of this kind before. It also quoted legal experts as saying that investigations into such espionage cases could take anywhere from a year to a year and a half.