Turkish President Recep Tayyip Erdogan on Thursday threatened to expel ambassadors from the US, Germany and eight other western countries after they issued a joint statement in support of a jailed activist.
Parisian-born philanthropist and activist Osman Kavala, 64, has been in jail without a conviction since 2017, becoming a symbol of what critics regard as Mr Erdogan's growing intolerance of dissent.
The 10 ambassadors issued a rare joint statement on Monday, which was distributed widely on their Turkish social media accounts, saying Mr Kavala's continued detention "cast a shadow" over Turkey.
"I told our foreign minister that we cannot have the luxury of hosting them in our country," Mr Erdogan told Turkish media.
Mr Kavala has faced a string of charges linked to 2013 anti-government protests and a failed military coup in 2016.
The US, Germany, Canada, Denmark, Finland, France, the Netherlands, New Zealand, Norway and Sweden called for a "just and speedy resolution to his case".
Mr Erdogan sounded outraged on his return flight from a tour of Africa.
"Is it within your boundary to teach such a lesson to Turkey? Who are you?" he told private broadcaster NTV.
The Turkish lira extended its fall into record-low territory against the dollar within moments of Mr Erdogan's comments, on concerns of a new wave of tension between Ankara and the West.
The diplomatic frictions were compounded when Financial Action Task Force, a global watchdog, placed Turkey under surveillance for failing to properly battle both money laundering and financing of terrorism.
Turkey joins a "grey list" of countries that includes Syria and South Sudan.
Mr Erdogan fought against the designation, introducing legislation that was ostensibly aimed to fight terror networks, but which critics said mainly targeted Turkish NGOs promoting pro-Kurdish causes and human rights.
The tension threatens to cast a pall over next week's G20 summit in Rome, where Mr Erdogan hopes to meet US President Joe Biden.
The two have had cold relations, in contrast to Mr Erdogan's personal friendship with former US president Donald Trump, who protected Turkey from sanctions for years.
The possible expulsion of US ambassador David Satterfield would come during a planned rotation of Washington's chief envoy to Ankara.
Mr Kavala has become a symbol to his supporters of the sweeping crackdown by Mr Erdogan after he survived a 2016 coup attempt.
He told AFP from his jail cell last week that he felt like a tool in Mr Erdogan's attempts to blame a foreign plot for domestic opposition to his nearly two-decade rule.
"The real reason behind my continued detention is that it addresses the need of the government to keep alive the fiction that the  Gezi protests were the result of a foreign conspiracy," Mr Kavala said.
"Since I am accused of being a part of this conspiracy allegedly organised by foreign powers, my release would weaken the fiction in question and this is not something that the government would like."
The protests to which he was referring began as rallies in May 2013 against an urban development plan for Gezi Park in Istanbul.
They spread across the country and grew into demonstrations calling for freedom of expression and assembly, and the press, and attacking what protesters considered to be Mr Erdogan's move away from Turkey's secularism.
Mr Kavala was acquitted of charges related to the Gezi rallies in February 2020, only to be rearrested before he could return home and thrown back into jail over alleged links to the 2016 coup plot.
The Council of Europe, the continent's top human rights watchdog, has issued a final warning to Turkey to comply with a 2019 European Court of Human Rights order to release Mr Kavala pending trial.
If Turkey fails to do so by its next meeting starting on November 30, the council in Strasbourg could vote to launch its first disciplinary proceedings against Ankara.
The proceedings could result in the suspension of Turkey's voting rights and even its membership.