"We demand that the United States stop victimizing Konstantin Yaroshenko and return him home," Zakharova said.
"This is not about medical assistance that can be postponed or may not be so necessary, but it is about urgent medical care that needs to be provided to a person in this situation," she said.
On Monday, Yaroshenko's wife, Viktoria, said that the United States had turned down her husband’s appeal for transfer to his country of citizenship. She had previously said that her husband was suffering from severe arthritis and was not receiving the necessary medical care.
The Russian pilot was captured in Liberia in 2010 and was transferred to the United States without an official extradition procedure, prompting protests from Russia. In 2011, a US court sentenced him to 20 years in prison for allegedly conspiring to smuggle drugs, charges the Russian national denies.
In 2016, the New York Court of Appeals refused to revise Yaroshenko’s sentence.