The United States on Tuesday delivered two F-16 fighter planes to Pakistan, the country's air force said.

"The two F-16s are of the same category, which are already operating with Pakistan Air Force," it said in a statement in Islamabad.

The purchase of these F-16s from the US was finalised a few months ago, it said.

Pakistan was expected to buy 75 F-16s from the US in a multi-billion dollar deal.

However, the two countries reached an understanding early November, allowing Islamabad to delay it at least until April next year.

The two planes, which were flown in to Islamabad on Tuesday, are upgraded versions of the old aircraft that Pakistan had received in the 1980s and would be added to the existing fleet of more than 30 F-16s.