ANKARA, Turkey — U.S. missions in Turkey have resumed processing visa applications by Turkish citizens on a “limited basis” after Turkey reassured Washington that no local staff would be detained or arrested for “performing their duties,” the U.S. Embassy said Monday.

Last month, the United States halted most visa services for Turkish citizens after Turkish authorities arrested Metin Topuz, a Turkish employee at the U.S. consulate in Istanbul, deepening already strained ties between Ankara and Washington. Turkey retaliated by halting visa services in the U.S. for Americans who want to travel to Turkey.

A U.S. embassy statement said it had received “high-level assurances” from Turkey that no additional local employees were under investigation. The Turkish government also gave assurances that local staff members would not be detained or arrested “for performing their official duties” and that Washington would be given information in advance if Turkish officials intend to arrest local staff in the future.

“Based on these preliminary assurances, we believe the security posture has improved sufficiently to allow for the resumption of limited visa services in Turkey,” the embassy said in a statement.

The Turkish Embassy in Washington posted a brief statement on Twitter, announcing that it was also resuming “limited” visa services. It later issued a second statement saying that no assurances were given to U.S. officials over any ongoing legal case. The statement also insisted that Topuz wasn’t arrested “not for performing his official duties but because of serious accusations” against him.

The announcements came a day before Turkish Prime Minister Binali Yildirim is due to travel to the United States to meet Vice President Mike Pence for talks aimed at mending frayed ties between the two NATO allies, including over Turkish demands for the extradition U.S.-based cleric Fethullah Gulen, who is blamed for last year’s failed coup, and Washington’s backing of Syrian Kurdish militia, whom Turkey considers to be terrorists.

Topuz was detained on charges of espionage and alleged ties to Gulen. He was the second local staff member at a U.S. mission in Turkey to be held. The U.S. Embassy denies the accusations against them.

The U.S. embassy said it continues to “have serious concerns about the existing cases against arrested local employees” as well as the cases of other arrested U.S. citizens. They include Pastor Andrew Brunson who was detained last year and is accused of terror-related charges for alleged ties to Gulen’s movement.

The Turkish Embassy statement said Ankara also has grievances concerning legal cases against Turkish citizens in the U.S. It didn’t elaborate.

Gulen denies involvement in the attempted coup.