US Ambassador to Russia John Tefft dismissed on Tuesday suggestions that Russian nationals Viktor Bout and Konstantin Yaroshenko could be transferred from prisons in the United States.

SAMARA (Sputnik) – Reports emerged last Tuesday and immediately denied by both sides that Russia and the United States were in confidential talks to swap Bout and Yaroshenko for Ukrainian national Nadezhda Savchenko.

Asked to comment on the possibility of Bout and Yaroshenko’s release by the RBC broadcaster's Samara affiliate, Ambassador Tefft issued a categorical denial, arguing that both Russian nationals’ guilt has been allegedly established in US court and that the two must serve their time.

Yaroshenko, sentenced to 20 years in prison for conspiring to import more than $100 million worth of cocaine into the United States, was arrested in Liberia in 2010 and was later extradited to the United States by Liberian authorities.

Bout, convicted on charges of conspiring to kill US nationals and conspiracy to sell weapons to a designated terrorist group (FARC guerillas) in Colombia, was extradited from Thailand to the United States and is now serving a 25 year sentence.

Two weeks ago, Savchenko was sentenced to 22 years in prison after being convicted in a Russian court of guiding artillery that killed Russian journalists Igor Kornelyuk and Anton Voloshin in eastern Ukraine on June 17, 2014. Her sentence came into force on Tuesday, April 5.

Russian Deputy Foreign Minister Sergei Ryabkov said on Monday that Moscow considered the swap a possibility under the Council of Europe's (CoE) Convention on the Transfer of Sentenced Persons. The United States is among 18 non-CoE states that are party to the convention.

Moscow maintains that Bout and Yaroshenko's arrests outside US territory are illegal.