The policy change, announced on Friday, will give those who want to work in the United States under a highly skilled worker visa program more time to wait for processing of their applications. The hitch is that their employers must be enrolled in the E-Verify programme, the system employers use to check to ensure they are hiring documented workers.

Until now, these students had 12 months to be accepted into the highly skilled worker visa programme, known as H-1B. Now they will have 29 months to stay in the United States as a student worker.

The change will affect about 23,000 foreign students getting degrees in science, engineering, math or technology during a time when the United States is creating more tech jobs but producing fewer college and university graduates with engineering degrees.

Part of the new policy is to create a ‘logical ladder’ to citizenship for foreigners who come to the United States to study these highly skilled fields, said Homeland Security's policy undersecretary, Stewart Baker.