Texas Gov. Greg Abbott (R) on Wednesday instructed state agencies to ban employee use of TikTok, joining a growing list of GOP governors taking action against the Chinese-owned social media app as national security concerns grow over the platform.

Abbott ordered all state agencies to immediately ban the use of TikTok on government-issued devices, citing the threat of the ruling Chinese Communist Party in obtaining private data about U.S. citizens on the app.

The governor also wrote a letter to Texas House Speaker Dade Phelan (R), urging him to pass legislation that would permanently codify his directive and ensure there are similar requirements for local governments.

“TikTok harvests vast amounts of data from its users’ devices — including when, where, and how they conduct Internet activity — and offers this trove of potentially sensitive information to the Chinese government,” the governor wrote. “While the federal government holds the ultimate responsibility for foreign policy issues, the State also has the responsibility and opportunity to protect itself.”

Abbott follows Maryland Gov. Larry Hogan (R), who on Tuesday banned the use of TikTok and several other foreign-based online entities for state agencies.

South Dakota Gov. Kristi Noem (R) also prohibited TikTok for state employees and contractors last month.

TikTok, which has more than 85 million users in the U.S., is owned by Chinese company ByteDance and is especially popular among younger Americans, raising concerns about the collection of data concerning minors.

U.S. Director of National Security Avril Haines warned last week that parents should be concerned about the use of TikTok, while a Federal Communications Commission member urged a ban on the social app last month.

The Chinese Communist Party maintains vast control over businesses in China.

Abbott on Wednesday noted that under a 2017 law, all companies are required to assist China in intelligence work, including on data sharing.

“The preservation of the safety and security of Texas is critically important,” he wrote to state government heads. “The threat of the Chinese Communist Party to infiltrate the United States continues to grow on multiple fronts.”