A Turkish employee of the US consulate in Istanbul has been sentenced to almost nine years in prison for aiding a terrorist organisation.
Metin Topuz was arrested in 2017 and accused of having links to an "armed terror group" that Turkey blames for a failed coup the previous year.
He was jailed for eight years and nine months in Istanbul on Thursday.
Mr Topuz denies the allegations. The US has said there is "no credible evidence" to support his conviction.
Mr Topuz is reported to have spent decades working as a translator and fixer for the US Drug Enforcement Administration (DEA) in Istanbul.
He was accused of making contact with officials, including police officers and a prosecutor, who were suspected of having ties to the US-based Muslim cleric Fethullah Gulen.
Turkey's President Recep Tayyip Erdogan has blamed the 2016 coup - which triggered a massive crackdown and saw scores of people killed - on Mr Gulen and people he accuses of being his followers. Mr Gulen denies any involvement.
In an earlier court hearing, Mr Topuz said his contact with the police and prosecutor was "part of my work as a translator and assistant liaison officer at the DEA".
He was acquitted on charges of espionage and trying to overthrow the government, but prosecutors later said he should face jail on the lesser charge of belonging to a terrorist organisation.
A lawyer for Mr Topuz told the AFP news agency that the court of appeal is due to decide whether to uphold his conviction.
The decision to arrest Mr Topuz in 2017 sparked a diplomatic row between Washington and Ankara and his trial has been a major source of tension.
The two countries mutually suspended visa services following his arrest and President Erdogan said the move was "very, very saddening".
In a statement on Thursday, the US embassy said it was "deeply disappointed" by Mr Topuz's conviction.
"We have seen no credible evidence to support this conviction and hope it will swiftly be overturned," it added.
At least 250 people were killed and more than 1,400 were wounded in the failed coup attempt in July 2016.
Since then, tens of thousands of people have been detained, with thousands more fired or suspended from public service.