(CNN) — The North Atlantic Treaty Organization (NATO) has officially banned its staff from downloading the social media app TikTok on NATO-provided devices, citing security concerns, according to two NATO officials familiar with the matter.

Nato officials sent a note to staff early Friday announcing the ban, the officials said. The note makes the ban official, but TikTok wasn’t really usable on previous NATO devices, officials said, due to internal technology restrictions.

“Cybersecurity is a top priority for NATO. NATO has strong requirements to designate apps for official business use. TikTok is not accessible on NATO devices,” a senior NATO official told CNN.

NATO is the latest government agency to ban the app out of fear that the Chinese government may gain access to TikTok’s user data through its Chinese parent company, Bytedance. The US, UK, Norway, European Parliament and other countries have banned the app on government devices.

TikTok CEO Shou Chew emphasized to US lawmakers earlier this month that the company was completely independent from Beijing, saying he “saw no evidence that the Chinese government had access to that data; we never asked for it, we didn’t give it to him.”

He added that TikTok transferred its data to the United States, to be stored on American soil by American company Oracle.

“So the risks would be similar to any government going to a US company and asking for data,” he said.

Even so, Western governments remain sceptical.

Secretary of State Antony Blinken testified before Congress earlier this month in a separate hearing, the same day Chew testified, that “TikTok has to be killed one way or another.” “It’s clear that we, the government and others, have recognized the challenges that exist and are taking steps to address them.”

CNN has reached out to TikTok for comment.