President Donald Trump has signed a proclamation imposing new restrictions on travelers from a handful of countries, including five that were covered by his travel ban that expired Sunday. Administration officials say the new measures are required to keep the nation safe.

The indefinite restrictions apply to citizens of Chad, Iran, Libya, Somalia, Syria, Yemen and North Korea. As part of the presidential proclamation, the U.S. will also bar the entry of certain Venezuelan government officials and their immediate families.

The changes will take effect October 18.

The announcement Sunday came on the same day that Trump's temporary ban on visitors from six Muslim-majority countries was set to expire.