Defence secretary Hamid Nawaz Khan was unaware of any plans by Washington to announce the release of the fighter jets during Musharraf's visit there, as reported by the US-based Defence and Foreign Affairs Journal and the Stratfor global affairs think-tank.

"We are trying our best not only to get F-16s but other things for the modernisation of our defence forces," Khan, a retired lieutenant general, said.

"I do not really know (about F-16 plans), but what really happens (during the visit) you cannot say.

"We will always buy the best equipment that can be bought for our armed forces."

A Pentagon spokesman on Thursday denied reports the jets would be released.

Washington blocked the release of 28 F-16s, already paid for by Pakistan, under the October 1990 Pressler amendment because it was unable to certify that Pakistan did not have a nuclear program.

Pakistan only went public with its nuclear program when it detonated several test devices in May 1998.

Additional economic and military sanctions have been slapped on Pakistan since 1990, largely over the 1998 tests and Musharraf's 1999 coup.

Sanctions on training and hardware sales were lifted rapidly after Musharraf swung Pakistan's support behind US-led efforts to topple its former ally the Taliban in Afghanistan, but there has been little trade.

"The embargo has been lifted only in theory. The flow of spares and equipment is still not coming," former secretary of defence production, Talat Masood, told AFP.

Musharraf has made the lifting of lingering sanctions a priority of his visit to the US.

He is due to arrive in the US from London later Friday for private time with his Boston-based son before starting the official leg of his visit on June 24 with talks at Camp David with President George W. Bush.

"President Musharraf during his visit to the US would like to see progress on the modernisation program of Pakistan's military," Khan said.

WAR.WIRE