Moscow, Russia - A Moscow court on Thursday rejected an appeal by Wall Street Journal reporter Evan Gershkovich, who was arrested for alleged espionage in Russia, to be released from pre-trial detention.

The court upheld its initial detention ruling for the US reporter, the Interfax news agency reported.

Gershkovich was described as smiling briefly as he entered the courtroom in a dark T-shirt and jeans. The US ambassador to Moscow, Lynne Tracy, was also present at the meeting.

Russia's Deputy Foreign Minister Sergei Ryabkov confirmed that the US had again requested consular access to Gershkovich.

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"This is now under consideration," he said.

John Kirby, the communications director at the US National Security Council, told CNN television that the court decision was "outrageous" but did not come as a surprise.

"We fully expected that the Russians would react this way and try to keep him in custody," Kirby said.

He said the US government was pushing to get more consular access to Gershkovich and bring him home if possible.

Gershkovich was arrested by the FSB secret service in March in Yekaterinburg, a city of over 1 million people in the Urals. He is accused of collecting secret information on Russia's military-industrial complex for US agencies.

The Wall Street Journal denies this and says Gershkovich was doing his work with an official accreditation. The US government is also demanding the immediate release of the correspondent.

Russia's judiciary had originally set the pre-trial detention until May 29, but extended it until the end of August.

If convicted, the reporter, whose parents were Soviet Jewish immigrants, faces up to 20 years in prison. The case is further straining the already tense relations between Washington and Moscow.