"Pakistan is a major non-Nato Ally, which has cooperated closely with us in the global war on terror. This proposed sale demonstrates our commitment to a long-term relationship with Pakistan," spokesman Tony Snow said in a statement.

"The proposed sale includes 18 new F-16 aircraft with an option to purchase another 18 new planes, a support package for up to 26 used F-16s, a munitions package, an upgrade package for Pakistan's current fleet of 34 F-16s, and logistical support," Snow said.

US President George W. Bush's administration notified the US Congress of the plan on June 28, said Snow, according to whom the proposed package is valued at approximately five billion dollars.

Pakistan agreed in April to purchase a scaled-down package of US F-16 fighters after foregoing a larger purchase to finance relief efforts after last year's devastating earthquake, which killed more than 73,000 people.

Washington had blocked the sale of F-16s to Pakistan for 15 years to protest its nuclear weapons programme, but gave the green light in March 2005 to reward the South Asian ally for its help in the "war on terror".

Pakistan said it expected the current deal to materialise.

"We do not think that there would be any revocation of the deal and we have no such fears. We know that the US administration is committed to providing aircraft to Pakistan," foreign ministry spokeswoman Tasnim Aslam told AFP.

"We do not entertain any suspicion that the US would not honour the deal," Aslam said.

Pakistan already has more than 30 multi-role F-16s made by US aerospace giant Lockheed Martin Corp.

In New Delhi, a spokesman for the Indian foreign ministry said the move would not help improve ties between the South Asian nuclear-armed rivals.

"This has been the subject of discussion with the US government in the past. In fact, the prime minister himself has expressed disappointment at the US approach to President Bush," spokesman Navtej Sarna told reporters.

"We can reiterate our position that this step is not conducive to improving ties between India and Pakistan," Sarna said.

India and Pakistan both claim Kashmir in full and have fought two of their three wars over the scenic Himalayan region.

Since January 2004 they have been engaged in a peace process to resolve all their pending disputes, including the one over Kashmir.