Harvard University has advised international students to return to campus before September 15, as major changes to US student visa rules are set to take effect on that date.

Under the current system, F-1 visa holders are allowed to stay in the United States under the “duration of status” provision, meaning they can remain for as long as their studies continue.

From September 15, students entering the US will be granted F-1 permission for a maximum of four years. In addition, the post-study grace period to leave the country will be reduced from 60 days to 30 days.

Students who need to stay beyond the shortened period will have to apply separately for an extension. Harvard noted that those already in the US when the rules begin may be covered under interim arrangements, while those travelling abroad and returning after the date may face different admission procedures.