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, according to a Moscow court.

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

In secret and short proceedings that were closed to the press on Thursday, Moscow’s Lefortovo court ruled that Mr. Gershkovich’s pretrial detention, which was previously extended from May 29 to Aug. 30, would again be extended until Nov. 30.

The arrest of Mr. Gershkovich marked 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 as long as 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.

Earlier 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 “continues 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.

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