Russia is hopeful it can agree a prisoner swap with the US that would include infamous arms trafficker Viktor Bout, known as the Merchant of Death.
It is the first time US or Russian officials have publicly said Bout could be part of an exchange.
Deputy Foreign Minister Sergei Ryabkov said on Friday he hoped the prospect of a swap had “strengthened”.
The US has previously said it was eager to organise a prisoner swap to release US basketball player Brittney Griner.
She was convicted of illegal drug possession in August after cannabis oil vapes were found in her bags as she tried to enter Russia.
The double-Olympic winner has been sent to a penal colony in a remote region south-east of Moscow.
On Friday Mr Ryabkov said a “common denominator” had not yet been reached between the US and Russia, but “it is undeniable that Viktor Bout is among those who are being discussed [for exchange] and we certainly count on a positive result”.
He also said Bout had been “persecuted” in the United States and wished him the “firmness of will and spirit” to cope with his incarceration.
Bout – a former Soviet air force officer – was extradited from Thailand to the US in 2010, after a sting operation by the US Drug Enforcement Agency (DEA).
One of the world’s most infamous arms dealers, his exploits are so notorious that they inspired a Hollywood film and led to his nickname.
He was sentenced to 25 years in prison after being found guilty of conspiracy to kill Americans and US officials, delivering anti-aircraft missiles and aiding a terrorist organisation.
He claimed he was simply an entrepreneur with a legitimate international transport business, wrongly accused of trying to arm South American rebels – the victims of US political machinations. BBC