By Sima Qunsol

The United States Embassy in Turkey released a statement on Thursday condemning Turkey's arrest of a U.S. Consulate staff member, who was taken in along with suspects linked to the Gulen movement during last year's failed coup.

Turkey on Wednesday sentenced over three dozen government militants to life in prison for their involvement in the attempted assassination of Turkish President Recep Tayyip Erdogan last year.

The U.S. said it is "deeply disturbed" by the arrest of a U.S. citizen working at the U.S. Consulate General Istanbul, emphasizing that the allegations are groundless and "wholly without merit".

Wednesday's sentences came after a series of arrests over similar allegations, all part of a probe into the Gülen movement.

On Tuesday, the government issued arrest warrants for 142 members of ministry staff for their suspected use of the By-Lock App, an encrypted messaging system reported to have been used by the targeted movement during last year's attempted coup.

The U.S. vowed in the statement to ensure its citizens are "accorded due legal process in accordance with the Turkish constitution and international legal norms."