In the 1990s Venezuela requested a batch of F-16C/Ds to update its F-16 fighter fleet, but the U.S. government blocked the request. In October 1997 the U.S. government approved the sale of the two crash replacement F-16s, but subsequently halted the sale. In 2005 a contract with Israel Aircraft Industries to upgrade Venezuela's F-16s was frozen following U.S. pressure. Chávez subsequently accused the U.S. of delaying the sale of spare parts to maintain Venezuela's F-16s. After remarks by Chávez that he would sell or lend the 'unused' F-16's to any country that wanted them, including Iran, the U.S. Government agreed to supply the spare parts; however, the shipment was detained at the Customs Office in Maiquetia International Airport due to security concerns.