The last three of 18 new and upgraded F-16 fighter jets from the United States arrived in Pakistan, a report by the Indo-Asian News Service said.

One F-16 D Block 52 and two F-16 Block 15 Mid-Life Upgrade aircraft arrived from the United States at Pakistan's air force base Shahbaz, the air force said in a statement.

The D Block aircraft is new but the Block 15 aircraft had been sent back to the United States for improvements, the Indo-Asian report said.

Improvements were specifically for strike precision upgrades and for better night vision flying capability in Lockheed Martin's single-engine F-16 Fighting Falcons.

The F-16 program included purchase of 18 new jets, upgrade of 35 older aircraft from the existing fleet and those purchased from the United States under Excess Defense Articles program.

The Indo-Asian report said the three-part, $3.1 billion F-16 program was one of the largest defense procurements made by the government in the face of increasingly difficult budget restrictions.

Initially, Pakistan had intended to purchase 36 new aircraft but the shopping list had to be halved because of strong financial crunch, particularly in the aftermath of the 2005 earthquake, the report said.

Pakistan paid for the new aircraft as well as munitions from cash resources but the mid-life upgrades were financed partly through the U.S. Foreign Military Funding assistance. The deal was done on the understanding that Pakistan would make the aircraft available to conduct tactical precision strikes against al-Qaida and Taliban targets in tribal areas, the report said.

The arrival of the planes from the United States comes in the same week as Turkish Aerospace Industries also delivered three modernized F-16 aircraft to Pakistan.

Turkey's semi-official Anatolia news agency reported that Turkish Defense Industry Undersecretary Murad Bayar said Turkey and Pakistan have successfully cooperated on a wide range of technologies, including radio, electronics and military information systems.

TUSAS signed the contract with Pakistan's Defense Ministry in June 2009 after a tender to upgrade 41 of Pakistan's F-16 under Islamabad's Modernization - Peace Drive II program, the Anatolian news agency said.

Peace Drive II involves the upgrade of 41 older F-16s under a contract signed in 2009 and will run until September 2014. Work consists mostly of avionics and structural updates of older F-16s to bring them near the capability of the F-16 Block 52s.

TAI said it also is training 72 Pakistani maintenance personnel.