Evan Gershkovich, the Wall Street Journal reporter detained in Russia, is expected to appear in court.

The Wall Street Journal reporter charged with espionage in Russia is expected to appear in a Moscow court on Tuesday for a hearing to appeal his pre-trial detention, a case that has brought relations between the United States and Russia to a new low.

The reporter, Evan Gershkovich, 31, was arrested by Russian security services in late March and formally charged with espionage. The Journal and the Biden administration vehemently deny the accusations and have called for his immediate release.

Mr. Gershkovich will appear in person in Moscow City Court, according to Zona Media, a Russian news website, citing the court’s spokesman. The hearing is expected to take place behind closed doors.

The court could allow Mr. Gershkovich to be moved to house arrest, but such a step appeared to be extremely unlikely given the gravity of the charges against him. If convicted, Mr. Gershkovich faces up to 20 years in a Russian penal colony.

The hearing comes a day after the U.S. ambassador in Moscow met with Mr. Gershkovich at the Lefortovo Prison in Moscow. It was the first consular visit since he was detained and followed repeated calls from the State Department for Russia to grant access to him.

“He is in good health and remains strong,” Lynne M. Tracy, the ambassador, said in a brief statement posted on Twitter. “We reiterate our call for his immediate release.”

Also Monday, Linda Thomas-Greenfield, the U.S. ambassador to the United Nations, condemned Mr. Gershkovich’s detention in a statement made on behalf of dozens of countries. “We urge Russian Federation authorities to release those they hold on political grounds, and to end the draconian crackdown on freedom of expression, including against members of the media,” she said.

Mr. Gershkovich’s case, the first time a Western journalist in Russia has been charged with espionage since the Cold War, has prompted an outpouring of support from Mr. Gershkovich’s colleagues and press freedom groups.

The State Department last week designated Mr. Gershkovich as “wrongfully detained,” which means that the U.S. government sees him as the equivalent of a political hostage held on fabricated charges. It also reflects a concern among U.S. officials that Mr. Gershkovich’s case appears to signal an even more severe Kremlin crackdown on independent news media outlets and the free flow of information within the country.

While the Kremlin spokesman, Dmitri S. Peskov, has repeatedly claimed that Mr. Gershkovich was caught “red-handed,” the Russian authorities have not provided any evidence to back up their accusations.

A son of Soviet Jewish émigrés, Mr. Gershkovich was detained on March 29 while on a reporting trip in the city of Yekaterinburg and transferred to Moscow, where a district court formally arrested him. A Moscow court placed Mr. Gershkovich into pretrial detention until May 29, according to the Tass news agency, although that term is likely to be extended.