Russia's Moscow City Court refused to release Wall Street Journal reporter Evan Gershkovich from pretrial detention Thursday, rejecting an appeal from the American journalist who is being held on espionage charges. Gershkovich's parents attended the hearing.

Authorities have not offered any evidence to support their allegations against Gershkovich; the U.S. says he is being "wrongfully detained" and must be released immediately.

Gershkovich's parents traveled to Russia to hear the decision, and they were able to briefly see their son and talk with him through an opening in the glass and metal cage from which he viewed Thursday's proceeding. Gershkovich, wearing a dark T-shirt and jeans, was seen smiling as he stood talking with his mother.

Gershkovich has been detained since late March, when he was taken into custody by Russian security agents during a reporting trip near the Ural Mountains in western Russia. His appeal sought to overturn a court ruling in May that extended his pretrial detention for three months, through at least August 30.

The court noted that the charges accuse Gershkovich of collecting information about Russia's military-industrial complex. Foreign Ministry spokeswoman Maria Zakharova said in April that Gershkovich "was caught red-handed and his journalistic status ... was merely a cover for spying."

Despite that claim, Russia's move to detain a U.S. journalist for the first time in decades is widely seen as an escalation of two items on the Kremlin's agenda: seizing leverage in negotiations over disputes with the U.S., and suppressing journalism operations inside Russia as it wages war on neighboring Ukraine.

"This whole legal process as it relates to Evan is a sham," U.S. State Department Principal Deputy Spokesman Vedant Patel said on Wednesday. "We've been very clear that Evan is wrongfully detained, being wrongfully detained and targeted for simply doing his job" as a journalist.

Gershkovich was detained months after Moscow freed WNBA star Brittney Griner in a prisoner swap in exchange for the U.S. releasing convicted Russian arms dealer Viktor Bout.

Former U.S. Marine Paul Whelan has been in Russian custody for more than four years after being arrested in late 2018. He was later sentenced to serve 16 years in a Russian penal colony on what the U.S. says are bogus espionage charges. The Biden administration has promised to keep working toward his release.