The detention last week of Turkish national Metin Topuz, who works for the US Consulate in Istanbul, sparked a sudden deterioration in relations and prompted Washington to suspend all its non-immigrant visa services
in the country. Ankara responded by doing the same.
Topuz was arrested on terrorism charges, but little else is known about the allegations against him. US Ambassador John Bass complained Wednesday that Turkey had left the United States in the dark as to why he was detained.
"There are ... times that our two governments do not seem to be eye to eye (on) specific aspects of our bilateral relationship. We are observing one of those this week as a result of actions the Turkish government took against some of our local staff," Bass said at a news conference in Ankara.
He said it was difficult to comment on Topuz's case "because again there has been no official communication from the Turkish government regarding these matters for the ostensible evidences."
He added that accusing US consular employees of terror-related crimes was "a very serious allegation."
His comments are the latest in a terse exchange of words to mark deteriorating relations between the United States and Turkey.
Turkish Foreign Minister Mevlut Cavusoglu spoke to US Secretary of State Rex Tillerson on Wednesday for the first time since the visa crisis began, Turkish foreign ministry sources told CNN.
State Department spokeswoman Heather Nauert said Tillerson "conveyed to the foreign minister his profound concern over the detentions of Turkish national employees of our diplomatic mission to Turkey and of several American citizens."
The two NATO allies have feuded over several issues, including the United States' refusal to extradite Muslim cleric Fethullah Gulen. Gulen lives in exile in Pennsylvania and Turkey blames him for coordinating an attempted military coup last year.
There have also been complaints by Ankara over Washington's support for Kurdish fighters in Syria. Ankara considers them terrorists while Washington sees them as the backbone of Syria's anti-ISIS forces.
And now a string of arrests of US citizens -- as well as Turkish nationals working for the US mission -- has become a new wedge between the countries.
Erdogan snubs Bass
Washington's visa freeze has caused ire in Ankara, and Bass' comments come a day after President Erdogan said he would no longer recognize Bass as the US' representative. Bass is an outgoing ambassador and will soon take up a new post in Afghanistan.
"In fact, this ambassador is doing his farewell visits," Ergodan said Tuesday.
"And right now, be it our Cabinet ministers, parliament head -- and I personally am not accepting his farewell visit, and will not do so, because we do not see him as a representative of the United States in Turkey -- let me say that clearly."
But Bass defended the visa freeze Wednesday as a necessary measure while trying to calm the waters.
"It is important to reiterate that it was not a decision we took lightly. It was a decision that we took with a great deal of sadness," he said.
The ambassador said, however, that he was willing to work with Turkish officials to resolve the problem quickly.
Turkish Prime Minister Binali Yildirim said Wednesday that he hoped relations with Washington would normalize soon.
"We will not abandon common sense about the the visa crisis with USA. Our hope is the relations will go back to normal shortly," he said, state media reported.
Spate of US-linked arrests
The United States has been rattled by the arrests of US citizens and its consular staff, detained as the government continues with a widespread purge after the coup attempt.
Turkey is also holding an American pastor, Andrew Brunson, whom Erdogan has suggested could be exchanged for Gulen.
It appears that foreign journalists are now being targeted as well.
A Wall Street Journal reporter, Ayla Albayrak, was sentenced in absentia Tuesday to two years in prison for spreading "terrorist propaganda." The case was brought forward over her coverage of a Kurdish militant insurgency, according to the Wall Street Journal. Albayrak is a dual Turkish-Finnish national and is now in New York.
And on Wednesday, German journalist Mesale Tolu went on trial for terror offenses and could face 15 years in prison if convicted.
She is charged with being a member of the Marxist-Leninist Communist Party -- labeled in her indictment as an "armed terror organization" -- and with spreading "terrorist propaganda."
She has been in prison for more than five months with her young son. Her child's father was also detained.
Eleven Germans are being held in Turkey for political reasons
, the German Foreign Ministry has said. Chancellor Angela Merkel has described the arrests as "unjustified"
and repeatedly called for the prisoners' release.
While not commenting on specific cases, Turkish officials said charges against Turkish and foreign journalists are usually linked to their membership in "terrorist organizations" or their creation of "propaganda" on their behalf.
At least 81 journalists are behind bars in Turkey, according to the Committee to Protect Journalists.