Foreign officials who enable the forced return of Uyghurs and other ethnic or religious groups to China face visa restrictions in the United States, Sec. of State Marco Rubio announced Friday.

The State Department unveiled visa restrictions on foreign government officials who are thought to be responsible for aiding illegal immigration into the U.S., part of a wider effort by President Trump’s administration to crackdown on immigration.

The U.S. State Department has imposed visa sanctions on an unspecified number of current and former Thai officials for their role in last month’s deportation of 40 Uyghur asylum seekers to China.