"Some concerns about US trade policy mar an otherwise excellent commercial relationship," Pakistani Prime Minister Zafarullah Khan Jamali said in a speech to the US Chamber of Commerce, a leading business group.

"Large portions of imports enter the United States under special trade arrangements. This leaves countries such as Pakistan at a severe disadvantage ... This should be corrected," Jamali said.

Since taking office in January 2001, the Bush administration has concluded free trade agreements with Chile and Singapore and launched negotiations with five Central American countries, members of the Southern African Customs Union, Morocco and Australia.

The united States also has unilateral trade preference programmes for countries in sub-Saharan Africa, Central America and the Caribbean and the Andean region of South America.

The trade deals give participating countries an advantage in the US market by eliminating tariffs on their imports.

Pakistan, an ally in the US war on terror, has been in the waiting line of a free trade pact. A US trade official said it could be some time before that happens.

"It's not imminent. We're talking an indefinite point in the future," Assistant US Trade Representative for South Asia Ashley Wills told Reuters. "We have some others we want to do first. We'll see how they go."

US officials have indicated Sri Lanka could beat Pakistan as the first country in South Asia to begin free trade talks with the United States.

Pakistan's exports to the United States totaled $2.30 billion in 2002, up only slightly from 2001. About half of the shipments were cotton apparel products.