(Reuters) - Talks between Russia and the United States on securing an exchange of high-profile prisoners are making only sporadic progress, a top Russian diplomat said in comments published on Thursday.
The two countries have been examining ways of conducting an exchange to enable jailed Americans Brittney Griner and Paul Whelan to go free. Moscow has made it known it would like convicted arms dealer Viktor Bout to be included in any deal.
"The questions of exchanges are examined in a separate channel designated by the presidents and sometimes this goes well and sometimes not so well," Ryabkov told Izvestia.
"This is an extremely delicate topic - we are talking about the fate of individuals."
Ryabkov said the main task was to secure the freedom of people convicted in the United States under articles of law that were "essentially punitive".
He made no reference to any of the jailed individuals under consideration, but the article in Izvestia featured a photograph of Bout behind bars.
Ryabkov said some prisoners under discussion had been "quite simply kidnapped in a most barbaric way in third countries. They have to be brought home and work on this is continuing."
Bout was sentenced to 25 years in prison by a U.S. court in 2012 on a series of charges after being detained in Thailand and extradited to the United States. Russian officials have said he is innocent.
Griner was taken last month to a penal colony southeast of Moscow to serve a nine-year drug sentence after being arrested in February with vape cartridges containing cannabis oil. Griner says she had no criminal intent.
Whelan, a former U.S. Marine, is serving 16 years in the same region on charges of espionage, which he denies.
Ryabkov no predictions on "how, when or even whether" the talks would prove successful.
"We are not going begging on this and are asking for no favours," Izvestia quoted him as saying.
Elizabeth Rood, the U.S. charge d'affaires in Moscow, told Russia's state-owned RIA news agency last month that the Russian side has "not provided a serious respone" to U.S. proposals.
(Reporting by Ron Popeski; Editing by Stephen Coates)