Turkish President Recep Tayyip Erdoğan has slammed ten ambassadors over their call for the release of a jailed philanthropist.
Erdoğan said that their demands were "irresponsible" and threatened to expel them from Turkey, according to national media.
Ambassadors representing ten different countries were summoned to Turkey’s foreign ministry on Tuesday.
They included officials from France, Germany, the Netherlands, Denmark, Sweden, Finland, Norway, the United States, Canada, and New Zealand.
The ambassadors had released a statement calling for a "fair and timely" resolution to the case of Osman Kavala.
The letter stated that delays in Kavala's case "cast a shadow over respect for democracy, the rule of law and transparency".
The move angered government officials in Ankara, who accused the countries of meddling in the Turkish judiciary.
Turkey's foreign ministry said in a statement that their letter was "impertinent" and "unacceptable."
"Turkey is a democratic country governed by the rule of law that respects human rights ... the Turkish judiciary will not be influenced by such irresponsible statements," the ministry added.
Kavala, a businessman and philanthropist, has been held in prison since 2017 despite never being convicted of a crime.
The 64-year-old was acquitted last year of charges linked to nationwide anti-government protests in 2013 that started at Istanbul’s Gezi Park.
But the ruling was overturned and he was also charged with espionage and attempting to overthrow the government in connection with a failed military coup in 2016.
Kavala faces a life term in prison without parole if convicted. The activist has rejected all charges against him while human rights groups have denounced the case against him as being politically motivated.
The European Court of Human Rights called for Kavala's "immediate release" in 2019, stating that his imprisonment was meant to silence him, and was not supported by any criminal evidence. Turkish authorities have ignored the ruling.
The Council of Europe says it will start infringement proceedings against Turkey if Kavala is not released by the end of November.
The next hearing in Turkey in Kavala's case will be held on November 26, more than four years after he was first imprisoned.
Separately, Turkish prosecutors have also ordered the arrest of 158 military personnel, including 33 serving officers, in an operation targeting supporters of Fethullah Gülen.
Gülen, a Muslim cleric, has been blamed by the Turkish government for the failed 2016 coup attempt.
The former ally of Erdoğan lives in exile in the United States and denies any links to the coup.
The latest investigation, stretching across 41 provinces, is part of a five-year-old crackdown against the Gülen's network.