The US and Turkey have imposed travel restrictions on each other’s citizens in an escalating diplomatic spat that highlights worsening relations between Ankara and its western allies.

Washington said late on Sunday it was suspending the processing of all non-immigrant visas in Turkey due to “recent events” that “have forced the United States government to reassess the commitment of the government of Turkey to the security of US mission facilities and personnel”.

Ankara responded in the early hours of Monday with an identical statement, imposing tit-for-tat measures and suspending the processing of visas in its embassy and consulate in the US. It also shut down its online visa system for US citizens.

The Turkish president, Recep Tayyip Erdoğan, described the US decision to suspend visa services as upsetting. “For the embassy in Ankara to take such a decision and implement, it is upsetting,” he told a news conference during a visit to Ukraine.

The Turkish move has effectively closed its borders to American visitors residing in the US or elsewhere, unless they can obtain visas from diplomatic missions outside their home country.

A rift between Turkey and the west has broadened in the aftermath of last year’s coup attempt, divergence over the war in Syria, and a crackdown against alleged putsch collaborators.

The US government’s restrictions appeared to be linked to the arrest last week of a local consulate employee in Istanbul over alleged links to the movement of Fethullah Gülen. Gülen, an exiled preacher based in Pennsylvania, is widely believed in Turkey to have orchestrated last year’s coup attempt. Ankara has long demanded the cleric’s extradition.

The US embassy said it was “deeply disturbed” by the arrest, and said the allegations were “wholly without merit”.

Later on Monday, in another escalation, the Turkish foreign ministry said it had summoned the American charges d’affaires, and the Istanbul prosecutor’s office said it had ordered the questioning of another US consulate official as a suspect in an unidentified case.

The prosecutor’s office said it had detained the man’s wife and child.

The state-run Anadolu agency said foreign ministry officials had urged the diplomat to have the embassy reverse its decision to halt visa processing, saying it could lead to an “unnecessary escalation” of tensions.

The national carrier Turkish Airlines said it would offer refunds to passengers travelling between the US and Turkey until the end of October.

Washington once saw Turkey as key to battling Islamic State militants and other terror groups in Syria and Iraq, but relations between the two allies declined under Barack Obama.

Ankara objected to the former president’s lack of willingness to intervene forcefully in the war in Syria against the forces of Bashar al-Assad, as well as Washington’s support for Kurdish militias fighting against Isis in Syria. Turkey considers the People’s Protection Units (YPG) an affiliate of the Kurdistan Workers party (PKK), a separatist insurgency and designated terrorist group.

Turkey was also angered by how slow the US was to condemn last year’s coup attempt and unwillingness to extradite Gülen. Turkish security personnel were indicted this year for attacking demonstrators during a visit by Erdoğan to the US.

Observers had expected relations to improve under the administration of Donald Trump, who has long expressed admiration for Erdoğan, a strongman leader with a reputation in the west for not tolerating critics. However, a US initiative to directly arm the Kurdish militias fighting in Syria caused diplomatic relations to deteriorate further.

The Turkish lira plummeted to its lowest value in months over the latest crisis, which will limit the influx of tourists to the country after a slow recovery.

Source: theguardian.com