The US Department of Defense (DoD) is to block US government deparments using foreigners in IT projects.
The measures, which are a reaction to the 11 September bombing, would prevent most non-US citizens from working with unclassified information, department officials said.
Currently there are restrictions on those who work on technical projects dealing with classified information, but in a post-11 September world, the department is considering extending the policy.
The department said it didn't know how many people would be affected by the policy, but it would hit contractors working in US government departments.
Pete Nelson, deputy director for personnel security, said in a statement that it was in the interests of the department to ensure that any person accessing unclassified but sensitive DoD IT systems was reliable and trustworthy.
But the move has been attacked by foreign workers in the US who point out that there is little evidence that technical workers were high security risks.
The 11 September bombers didn't hold work permits and few tech workers come from terror hotspots such as Saudi Arabia and Afghanistan.
Murali Krishna Devarakonda, a member of the board of directors of the Immigrants Support Network, warned that the United States was shooting itself in the foot by banning those with technical skills when the country lacks people with those abilities.
Freshly launched 11nm Qualcomm silicon will come with Adreno 612 GPU
Are pinning down the exact rate of expansion of the Hubble constant
RISC OS 5 to form the basis of RISC OS Open after Castle Technology sells to RISC OS Developments
A smartphone maker fiddling its benchmarking scores? That's unusual, isn't it?