ISTANBUL (Reuters) - The United States and Turkey lifted all visa restrictions on Thursday after Washington said Ankara had kept to assurances no further U.S. mission staff would be targeted for performing official duties, following detention of two earlier this year.

General view of the U.S. Embassy in Ankara, Turkey, December 20, 2016. REUTERS/Umit Bektas

But Turkey swiftly denied having granted such assurances in the affair that has tested relations since the two local employees of the U.S. consulate in Istanbul were held on suspicion of ties to last year’s failed coup against President Tayyip Erdogan.

The United States suspended visa services at its missions in Turkey in October and Turkey reciprocated. In November, Washington said it was resuming limited services upon getting assurances on the safety of its local staff.

“Based on adherence to these assurances, the Department of State is confident that the security posture has improved sufficiently to allow for the full resumption of visa services in Turkey,” the U.S. Embassy in Ankara said on Thursday.

It said the United States continued to have concerns about the two employees detained.

Turkey, while announcing the end of restrictions on the issue of visas to U.S. citizens, took issue with the U.S. declaration.

“We do not find it right for the United States to claim it had received assurances from Turkey and misinform the U.S. and Turkish publics,” the Turkish Embassy in Washington said in a statement.

Turkey’s lira firmed to 3.78 against the U.S. dollar after the statement, its highest level since Oct. 31, and the main share index BIST100 climbed 2.08 percent to reach its highest closing level ever.

Relations between the two NATO allies have become strained in the last year with Turkey angered by what it sees as the U.S. reluctance to hand over Fethullah Gulen, whom Turkey blames for the coup attempt in July of 2016.

Turkey was further annoyed by U.S. military support for Kurdish YPG fighters in Syria, considered by Ankara to be an extension of the banned PKK which has waged an insurgency for three decades in southeast Turkey.

More recently, Turkey took a leading role in the United Nations to pass a resolution denouncing a U.S. move to recognize Jerusalem as the Israeli capital.