The US says it has held discussions with Russia aimed at bringing jailed American journalist Evan Gershkovich home – but that there is no “clear pathway” to his release.
Asked about a prisoner swap, National Security Adviser Jake Sullivan said the US was “prepared to do hard things” to get Mr Gershkovich back.
The Wall Street Journal reporter, accused of espionage, was arrested on 29 March.
The US says the case is baseless.
It accuses Russia of holding Mr Gershkovich for “leverage”.
Mr Sullivan’s comments on Friday confirmed an earlier Kremlin statement about “contacts” over the case.
He said that “there have been discussions, but those discussions have not produced a clear pathway to a resolution”.
“We are prepared to do hard things in order to get our citizens home, including getting Evan home. I do not want to give false hope,” he said. “We have a clear commitment and conviction that we will do everything possible to bring him home.”
On 22 June a Moscow court rejected an appeal to free Mr Gershkovich, 31, who is being held at Lefortovo, where the Soviet KGB formerly held dissidents.
On Tuesday the Kremlin said there had been “certain contacts” with the US over Mr Gershkovich’s case, suggesting the possibility of a prisoner exchange.
The previous day US ambassador Lynne Tracy was allowed to visit Mr Gershkovich in a Moscow prison for only the second time. He is the first Western journalist to be jailed in Russia since the Soviet era.
Russian embassy staff also recently visited Vladimir Dunaev, a Russian national detained in the US on cybercrime charges. He was extradited to the US from South Korea in 2021.
There is speculation that a new prisoner swap may be arranged.
The US has also been pressing for the release of Paul Whelan, a former US Marine who has been in jail for more than four years.
Mr Whelan is in Mordovia, an area far south east of Moscow known for harsh conditions in its prison camps.
And after being jailed for 10 months, basketball star Brittney Griner was released in December after the US brokered a prison swap and released Russian arms dealer Viktor Bout, who was imprisoned in the US over weapons smuggling.
