President Donald Trump has unveiled new visa restrictions that will limit the duration of stay for international students, exchange visitors, and foreign journalists in the United States.

Under the new policy announced by the Department of Homeland Security, DHS, most international students and exchange visitors will now be permitted to stay in the U.S. for a maximum of four years.

Foreign journalists will be issued visas valid for up to 240 days, while journalists from China will be restricted to 90 days.

Individuals seeking to remain beyond the approved period will be required to apply for an extension or exit the U.S. and reapply.

The rule is scheduled to take effect 60 days after publication, pending congressional review. It is expected to affect students resuming academic programs in August and September.

According to DHS, the policy addresses concerns that previous administrations allowed visa holders to stay “virtually indefinitely,” a situation the department says poses security risks and increases costs for taxpayers.

“Thousands of people remained on student visas for years by extending or changing their academic programs,” DHS stated, adding that the new measure is designed to strengthen monitoring of visa holders.

The announcement is part of President Trump’s wider immigration reforms. However, critics warn the policy could discourage international students and researchers from pursuing higher education in the United States.