The North Atlantic Treaty Organization didn’t shy away this week from speaking out about mass arrests in Turkey, one of its member states. But the United States, also part of the organization, hasn’t responded to the crackdown.

Turkish President Recep Tayyip Erdogan has thrown 47,000 people in jail since last summer and has eliminated about 120,000 government jobs. Turkish police arrested 1,000 people just this week for allegedly supporting Fetullah Gulen, an exiled Turkish cleric who the government believes is behind an attempted coup that took place last July.

NATO Secretary General Jens Stoltenberg warned Turkey Thursday about potentially unlawful arrests.

“Turkey has the right to protect itself and to prosecute those who were behind the failed coup attempt, but that has to take place based on the full respect of the rule of law,” he said. “I attach a great importance to these values myself and this is an issue we have discussed with the Turkish leadership.”

During his campaign, President Donald Trump called NATO “obsolete,” even hinting at possibly pulling out of the organization. He changed his tune in April after meeting with Stoltenberg.

Still, Trump has so far stayed mum in the face of the Turkish crackdown. Turkey remains a key U.S. ally in the Middle East, especially in light of ongoing conflict in Syria and the threat that the so-called Islamic State poses to both the U.S. and Turkey.

Trump called Erdogan to congratulate him after an April 16 referendum in the country, which vastly expanded Erdogan’s powers. If the two leaders addressed the questionable practices carried out in the lead-up to the vote, it wasn’t included in the White House’s statement about the call. They instead reinforced their joint interest in combating the Islamic State and dealing with the situation in Syria.