The United States has imposed restrictions on exports to China¡¯s biggest chipmaker SMIC after concluding there is an ¡°unacceptable risk¡± equipment supplied to it could be used for military purposes.

Suppliers of certain equipment to Semiconductor Manufacturing International Corporation will now have to apply for individual export licenses, according to a letter from the Commerce Department dated Friday and seen by Reuters.

The latest move marks a shift in U.S. policy from earlier this year, when applicants seeking ¡°military end user¡± licenses to sell to SMIC were told by the Commerce Department that the licenses weren¡¯t necessary, according to three people familiar with the matter.