"
The Muslim community is very upset
"
Faiz Rehman
American Muslim Council
Saudi and Pakistani men visiting or studying in the United States will be required to register with the government and provide their fingerprints and photographs.
They will have until February to provide documents to the country's Immigration and Naturalisation Service (INS).
Muslim groups said the measures were heavy-handed and unlikely to identify any terrorists.
"This is a kind of racial profiling which is unconstitutional in this country," Faiz Rehman of the American Muslim Council told the BBC's World Today programme.
But he advised those affected to abide by the new requirements to avoid being deported.
Fingerprinting
Both Saudi Arabia and Pakistan are supporting the US in its so-called war on terror.
Saudi Arabia looks set to take tit-for-tat measures against American citizens, including fingerprinting.
Pakistan wants the US measures reviewed.
"We are taking up the issue with US authorities at the highest level," it's deputy ambassador in Washington, Mohammed Sadiq, told the BBC Urdu service.
"In the meantime, we have asked our citizens to abide by US law."
Iran - which was already on the list - has decided to fingerprint visiting Americans, the official Iranian news agency IRNA reported.
Women excluded
Men from the first round of countries put on the list - Iraq, Iran, Libya, Sudan and Syria - had been ordered to register by Monday.
Men from Afghanistan, Algeria, Bahrain, Eritrea, Lebanon, Morocco, North Korea, Oman, Qatar, Somalia, Tunisia, the United Arab Emirates and Yemen must register with the INS by 10 January, 2003.
The programme does not affect permanent residents, "green card" holders, or naturalised citizens from those countries, as well as diplomats and people who have political asylum in the US.
Those who fail to register can be deported. Women and children were excluded because their numbers would have made the programme impossible to administer, the US Justice Department officials said.
American officials insist that the measures will not affect relations with Riyadh and Islamabad.
Visiting the Pakistani capital, the American Assistant Secretary of State for South Asia, Christina Rocca, praised Pakistan for its contribution to the US-led war on terrorism.
She said Washington is to donate surveillance equipment, worth $4.5m, to enhance security in Pakistan.