The Norwegian parliament has approved the purchase of four Lockheed Martin F-35 Joint Strike Fighters for training purposes ahead of a final decision set for next year on buying up to 52 additional jets, according to Reuters. Norway's Labour-led majority government fended off criticism of cost overruns and delays in the U.S. programme and secured broad parliamentary support to order training craft valued by U.S. officials at more than $400 million. "I am happy the parliament voted to support the purchase of four F-35 training aircraft," Defence Minister Grete Faremo said in a statement on Friday. NATO-member Norway's current fleet of U.S.-built F-16s, mostly from the 1980s, has been bombing Libyan targets. The F-35 trainers are to be delivered in 2016 from an early production run, before Lockheed Martin is done developing a final software package, senior ministry adviser Marita Isaksen Wangberg told Reuters. Norway's parliament approved a cost framework of 4.8 billion crowns ($865 million) for the planes, including contingencies and early operational costs. Faremo promised an external review of pricing before next year's final decision on replacing her country's aging F-16s. The U.S. Department of Defence's F-35 programme, restructured twice in two years, is currently expected to cost $382 billion. Eight allies, including NATO-member Norway, are pitching in on development costs. In 2009 the Norwegian government said the F-35 was a better fit than Saab's JAS Gripen. Wangberg said Norway tentatively plans to buy 56 jets at a base price totalling 42 billion crowns, or up to 72 billion with contingencies, with delivery in 2018. Critics said the training-craft purchase would effectively commit Norway to a whole fleet of F-35s even if costs surged, but the government said it could still switch to a different craft next year. Wangberg said the total number of jets is also subject to change.