To the dismay of the U.S. Bush administration, Pakistan and China have agreed to co-produce a new JF-17 fighter aircraft China's Chengdu Aircraft Design Institute is the architect of the JF-17 while its prototypes, first flown last year by Pakistani test pilots, were made by the Chengdu Aircraft Company based in Sichuan province, the Financial Times said Tuesday. The two countries are planning to produce at least 400 of the fighters, with half made on assembly lines in each country. At least one U.S. defense analyst said the Bush administration had little to worry about from a defense standpoint. "If you put it (JF-17) head to head against an F-16, it would probably last about five seconds," said Richard Aboulafia, aviation analyst at the Teal Group. However, the decision comes only two months after the United States offered to sell F-16 fighter aircraft to Pakistan, reversing sanctions applied almost 15 years ago over Islamabad's nuclear weapons program. There is also concern in Washington the aircraft could enhance China's ability to intimidate Taiwan, home to a strong and stubborn independence movement.