A US federal court in New York postponed a decision on whether to modify detention conditions for convicted Russian arms dealer Viktor Bout.

Judge Shira Scheindlin scheduled the hearing to address a complaint from Bout's defense attorneys about harsh conditions at the Metropolitan Correctional Center in New York, where Bout has been imprisoned for more than a year.

Scheindlin plans to reschedule the hearing soon, court sources told AFP.

"The judge did not make a decision," the source said.

Scheindlin rejected an appeal last Wednesday by Bout's defense team to dismiss the November 2 conviction against him. He is set to be sentenced March 12 on four charges for which he faces 25 years to life in prison.

Bout, 45, is accused of being the largest clandestine arms dealer in the world.

The former pilot and translator for the Soviet military was arrested in 2008 in Bangkok, Thailand.

He was flown to the United States in 2010 after a long legal battle to extradite him from Thailand that created tensions between Washington and Moscow.

Bout says he only transported arms as part of a legitimate air cargo business.

Bout was convicted of trying to sell surface-to-air missiles and other weapons to undercover agents. The agents posed as Revolutionary Armed Forces of Colombia guerrillas who planned to use the weapons against US counter-narcotics agents.