The pretrial detention of Evan Gershkovich, an American reporter for The Wall Street Journal who has been held in Russia since March, has been extended by three months, a Moscow court said on Thursday.

Mr. Gershkovich has been detained in Moscow’s Lefortovo prison on espionage charges that he, the U.S. government and The Journal have vehemently denied. The United States has said he is wrongfully detained.

In secret and short proceedings on Thursday that were closed to the news media, a Moscow court ruled that Mr. Gershkovich’s pretrial detention, which had previously been extended to Aug. 30, would now stretch until at least Nov. 30.

The arrest of Mr. Gershkovich was the first time since the end of the Cold War that an American journalist had been detained on accusations of spying in Russia. He could face a sentence of up to 20 years in a penal colony. At the time he was detained by the Federal Security Service, or F.S.B., Mr. Gershkovich was on a reporting trip in Yekaterinburg and had accreditation from Russia’s Foreign Ministry.

In a statement released after the hearing, The Journal said it was “deeply disappointed” that Mr. Gershkovich “continues to be arbitrarily and wrongfully detained for doing his job as a journalist” and called the accusations “baseless” and “categorically false.” The statement added that “journalism is not a crime.”

This month, Lynne M. Tracy, the U.S. ambassador to Russia, visited Mr. Gershkovich for the third time. The State Department reported afterward that Mr. Gershkovich continued “to appear in good health and remains strong, despite his circumstances.” American officials have said that they have been blocked from having regular consular access to Mr. Gershkovich.

In April, Secretary of State Antony J. Blinken said that Mr. Gershkovich had been wrongfully detained, a designation that essentially means that the U.S. government considers him a political hostage. Other Americans detained in Russia who have received this designation include the basketball star Brittney Griner, who was released in December 2022 in a prisoner exchange after being held for 10 months on accusations of drug smuggling and possession, and Paul Whelan, a former Marine and corporate executive who is serving a 16-year sentence on espionage charges that the United States calls politically motivated.

The Kremlin has acknowledged that Russia could be open to a prisoner swap for Mr. Gershkovich.