Ukrainian doctors have been granted access to pilot Nadia Savchenko, who is now held in a detention facility in Moscow, her lawyer Mark Feygin said.

"Ukrainian doctors have gone in to meet with Nadia Savchenko," Feygin said on Twitter on Saturday.

Ukrainian Foreign Minister Pavlo Klimkin has confirmed this information.

"Ukrainian doctors are already with Nadia thanks to the joint efforts made by Poroshenko and our consul," he said on Twitter.

The press service for the Ukrainian state presidential property management office reported on Friday that Ukrainian doctors had been denied a meeting with Savchenko.

A source told Interfax the doctors had been denied a meeting with Savchenko because they had no documents issued by the Russian Foreign Ministry.

Russian human rights ombudsman Ella Pamfilova later said she assumed full responsibility for the delay with the visit by Ukrainian doctors of Savchenko in the Moscow detention facility.

"I assume full responsibility for that. The Federal Penitentiary Service has nothing to do with this situation. Unfortunately, the procedures governing visits by foreign doctors to the detention facility turned out more complex than I thought and they require considerable additional approvals," Pamfilova told Interfax.

"After I was contacted by the Ukrainian authorities, I sent inquiries to all agencies in charge of this issue. I hope all procedures will be conducted in the nearest future and the Ukrainian doctors can visit Nadiya Savchenko," Pamfilova said.

The defense lawyers for Savchenko promised to file a complaint with the Russian Prosecutor General's Office about the actions taken by the Federal Penitentiary Service, which has barred doctors from meeting with their client, lawyer Nikolai Polozov said.

Savchenko has been in custody in Moscow since July 2014 on a charge of complicity in the killing of Russian journalists in eastern Ukraine. She denies the charge and claims she was abducted and brought to Russia. On December 13, she declared a hunger strike. On March 5, she agreed to eat broth because of her deteriorating condition.