Moscow expects the U.S. authorities to grant access to a Russian citizen held in the Guantanamo prison in Cuba, the Foreign Ministry said Wednesday.

"On the background of the reports about worsening situation in Guantanamo, lack of access to the Russian citizen causes our concern. We expect the U.S. colleagues would assist in organizing such a visit," the ministry's envoy for human rights, democracy, supremacy of law Konstantin Dolgov said in an online statement.

Ravil Mingazov, 44, was arrested in Pakistan in 2002 and has been held in the U.S. military prison ever since, along with seven other Russian nationals, who were extradited to Russia in 2004.

Dolgov reminded that an agreement on diplomats' visit to Mingazov was reached in 2012. However, the U.S. State Department informed Moscow on April 4 that Mingazov refused to meet with Russian diplomats, whoever they could be.

"We were offered to visit the Guantanamo base without a possibility to see the Russian citizen held in judicial limbo for over ten years," Dolgov said, adding that such an offer could not satisfy the ministry.

He urged the U.S. authorities to undertake efficient measures to close the prison as soon as possible, as demanded by international human rights groups.

U.S. President Barack Obama vowed to shut down the prison with over 150 detainees in 2009.