Pakistan has urged Washington to reconsider a new regulation requiring Pakistanis in the US to register with authorities.

Powell: Will inform the Attorney-General of Mr Kasuri's fears

Foreign Minister Khursheed Mahmood Kasuri told US Secretary of State Colin Powell in a telephone call the measures were causing ''a lot of despondency and concern'' among Pakistanis.

He said Pakistanis should be given special treatment because their country was a key ally in the war on terror.

Mr Kasuri is due to visit the United States next month.

Deportation threat

Mr Powell reportedly agreed to speak to US Attorney-General John Ashcroft about Mr Kasuri's concerns.

Thousands of immigrants in the United States rushed to comply with Friday's deadline to register under anti-terror laws introduced following the 11 September attacks.

Males over 16 from 13 mainly Muslim countries who are not permanent US residents had to register with the Immigration and Naturalisation Service (INS).

Friday deadline

Afghanistan Algeria Bahrain Eritrea Lebanon Morocco North Korea Oman Qatar Somalia Tunisia The United Arab Emirates Yemen

Those from Iran, Iraq, Libya, Sudan and Syria have already had to register under the scheme, while Saudis and Pakistanis have to comply by 21 February.

Anyone not complying may be detained or deported if their visas have expired or if they have otherwise violated US immigration law.

A Pakistani foreign ministry statement said: ''Mr Kasuri informed the Secretary of State that it was causing a lot of despondency and concern, not only amongst Pakistanis living in the US but also in Pakistan."

Mr Kasuri stressed that "not a single Pakistani was involved" in the September 11 attacks.

He said US-based Pakistanis were mostly economic migrants, supporting dependents in Pakistan, who "have no inclination for any disorderly behaviour and should not be a source of concern for the security agencies''.

Legal challenge

Many Pakistanis see the list as targeting Muslim countries, pointing out that North Korea is the only non-Muslim nation on the list.

Earlier detentions sparked angry protests

The US "special registration" effort has attracted widespread condemnation from civil rights groups and has been the subject of numerous legal challenges.

On Thursday a lawsuit filed by US-Muslim groups following the first wave of registration, seeking a block on further such detentions, was dismissed by a US federal judge.

The judge said that the men had been arrested legitimately by the INS for breaking immigration laws.

Up to 1,000 men from Iran, Iraq, Libya, Sudan and Syria, who came forward in the first registration processes, are being held by US authorities, according to human rights advocates.

US officials however, put the number at around 250.

Many illegal immigrants fear that they may suffer the same fate as those being held.