ANKARA - The US and Turkey said on Monday they resumed limited mutual visa services following an almost month-long suspension in a diplomatic row between the two NATO allies ahead of the Turkish premier’s visit to Washington.

The US decision to stop handing out visas took effect from October 8 and was followed by a tit-for-tat move by Turkey to stop giving Turkish visas to Americans.

Turkish Prime Minister Binali Yildirim will go to the US on Tuesday November 7 for a visit until November 10, during which he is due to hold talks with US Vice President Mike Pence.

The US embassy suspended visa services after one of the Istanbul consulate’s Turkish staffers was arrested, saying it needed to carry out a security assessment.

The employee was accused of having links to the group of US-based preacher Fethullah Gulen, blamed by Ankara for last year’s failed coup against President Recep Tayyip Erdogan. The employee remains in jail.

Metin Topuz was formally charged with espionage and seeking to overthrow the Turkish government last month, accusations the US embassy in Ankara said at the time were “wholly without merit”.

But the embassy on Monday said it had received “initial high-level assurances” from Turkey that “no additional local employees of our mission in Turkey (are) under investigation”.

It added that there were also assurances that local staff would not be “detained or arrested for performing their official duties”.

The Turkish embassy in Washington only said on its official Twitter account it was resuming visa services on a “limited basis” in the US.

Among the several Americans arrested in Turkey is pastor Andrew Brunson, who ran a church in the western city of Izmir. He has been held in Turkey since October 2016 on charges of being a member of Gulen’s group.

In March, a Turkish employee at the US consulate in the southern city of Adana was arrested on charges of supporting the Kurdistan Workers’ Party (PKK).

The US embassy said Turkish authorities indicated they would inform the US government in advance if they intended to detain or arrest a local employee in the future.

“We continue to have serious concerns about the existing cases against arrested local employees of our mission in Turkey. We are also concerned about the cases against US citizens who have been arrested under the state of emergency,” the embassy said.

Since last July’s coup bid, over 50,000 people have been arrested accused of links to Gulen and his movement under the state of emergency imposed in July 2016.

The mutual halt in the issuing of visas had become the most painful symbol of an increasingly troubled relationship between Washington and Ankara.

Turkey has pressed Washington for the extradition of the Pennsylvania-based Gulen, who denies any link to the coup bid.

The lack of movement on the issue has further strained ties already frayed over Washington’s support for a Syrian Kurdish militia that Ankara considers a terror group.

Ankara is also angry over the arrest in the US of Mehmet Hakan Atilla, deputy chief executive at state lender Halkbank, and the Iranian-Turkish businessman Reza Zarrab.

Their trial is scheduled to start on November 27.

Meanwhile, members of Erdogan’s security detail were indicted by US authorities after clashes with protesters during an official White House visit in May, infuriating the Turkish president.

Turkish officials had expressed hope of a new page in Ankara-Washington relations under President Donald Trump and Yildirim’s trip has been billed as the latest attempt to revive ties.