WASHINGTON, May 30. /TASS/. US Secretary of State Mike Pompeo urged the Russian authorities on Saturday to free Paul Whelan, accused of spying against Russia, claiming that the US national had been denied timely medical treatment.

"It is unacceptable that Paul Whelan has been denied necessary medical treatment until his condition became dire. We demand Paul’s release," Pompeo wrote on his Twitter page.

Earlier, Whelan’s attorney Olga Karlova informed TASS that her client had undergone an inguinal hernia surgery. The Russian Foreign Ministry said that Whelan was examined by doctors immediately after he had complained about health problems. The Foreign Ministry said in a statement that on the evening of May 27, Whelan complained of worsening of his health. Immediately after being examined by doctors, he was rushed to the Sklifosovsky Research Institute of Emergency Aid. "In early hours of the next day, Whelan underwent a minor surgery, which he had earlier rejected," the Russian Foreign Ministry stressed. On May 29, Whelan was returned to the pretrial detention center, where he is receiving the necessary medical aid.

US citizen Paul Whelan, who also holds British, Canadian and Irish citizenship, was detained by the Russian Federal Security Service (FSB) on December 28, 2018 in Moscow while on an alleged spy mission. A criminal investigation was launched against him on espionage charges carrying a punishment of up to 20 years behind bars.

Whelan denies all charges. His defense insists that the case is fabricated, while Whelan’s activity in Russia was of a strictly humanitarian nature. The court will pronounce Whelan’s sentence on June 15.