The State Department plans to drastically slash the number of U.S. embassies and consulates in Africa that can process visas for foreigners seeking to come to the United States.

The almost 50 U.S. embassies and consulates that are processing visa applications will be reduced to 20 in the coming weeks, according to three U.S. officials and an internal memo obtained by The Associated Press. There is not yet a set date for the change, but it is expected in June, according to the officials, who were not authorized to comment to the media and spoke on condition of anonymity.

The move is part of the Trump administration’s effort to crack down on issuing both immigrant and non-immigrant visas as part of its broader aim to limit immigration to the U.S. and clamp down on those who travel on temporary visas but then overstay them. The administration also has scaled back personnel at embassies and consulates around the world.

On a conference call last Friday, U.S. diplomats, including consular chiefs, were told the U.S. would be scaling back its visa services across Africa, according to one of the officials who was on the call.

Under a directive approved by Secretary of State Marco Rubio last week, the State Department will reduce consular operations in all but 20 “hubs” in Africa, according to the officials and the memo.

Visa processing in Africa has already been affected by a travel ban on certain countries as well as a requirement for applicants to post up to $15,000 bond in order to apply and more recently by restrictions caused by the Ebola outbreak.