The US government is to extend the period of security clearance for visa-holding scientists and students visiting the country from overseas, according to a joint statement by the US Department of State and Department of Homeland Security.
Tighter visa restrictions and lengthy background security checks since 11 September 2001, have meant that even foreign students who had studied in the United States for years have had to remain in their home countries, missing conferences or part of their academic year. This has deterred other students from visiting the United States.
Security clearances for students will now be valid for four years, those for scientists working in the United States on scholar and work visas will last two years, and those for researchers attending conferences will be valid for 12 months.
The Department of State also said it will continue to try to reduce the average length of time for security checks, which has decreased from 75 days to 14 days during the past year.Link to full Nature news story