WASHINGTON (Reuters) - The United States said on Tuesday it was “deeply troubled” by Turkey’s re-arrest of the chairman of the local arm of Amnesty International, and called on its NATO ally to end its state of emergency and safeguard the rule of law.

U.S.-Turkish relations have been strained recently by a series of disagreements, especially over the Syria crisis.

Taner Kilic was one of 11 human rights activists arrested last year on what Amnesty International has said were “bogus terrorism charges.” He is the only one of the 11 still jailed after eight months in detention, the rights group said.

Kilic was conditionally released last week, but the prosecution successfully appealed the decision and he was re-arrested before he had even arrived home, Amnesty said in a statement.

U.S. State Department spokeswoman Heather Nauert told a briefing the United States was “deeply troubled” by Kilic’s re-arrest on Feb. 1.

She said Washington was closely following Kilic’s case, as well as those against other human rights defenders, journalists, civil society leaders and opposition politicians detained in the state of emergency that followed a failed coup against President Tayyip Erdogan on July 15, 2016.

“We call on the Turkish government to end the protracted state of emergency, to release those detained arbitrarily under the emergency authorities and to safeguard the rule of law,” Nauert said, noting that the emergency had “chilled freedom of expression” and raised concerns about judicial independence.

In the year after the coup, Turkey arrested more than 40,000 people and fired 125,000, including many from the police, army, and judiciary. Erdogan blames the attempted coup on Fethullah Gulen, an exiled cleric and former ally based in the United States. Gulen has denied any role in the plot.