Defense Secretary Leon Panetta assured his Italian counterpart, Giampaolo Di Paola, that the United States remains committed to the F-35 Joint Strike Fighter during a meeting yesterday at the Pentagon, a spokesman said.

Panetta’s meeting with Di Paola came amid rising concerns over the program’s cost overruns and delays, and as some nations, facing budget woes, are rethinking the number of planes they intend to purchase.The Italian government reportedly said recently it planned to lower its buy from 130 F-35s to about 90.

“Secretary Panetta reiterated the United States commitment to developing the Joint Strike Fighter and the technology advancements both nations will receive as a result of fielding this 5th generation fighter,” Pentagon spokesman George Little said in a statement following the meeting.

Reduced buys domestically and internationally have sparked worries the plane’s unit cost will only increase. In outlining its fiscal 2013 budget request recently, the Pentagon said it was restructuring the program for the third time and would scale back buys of the aircraft to give it more time to mature, reduce concurrency costs and save about $15 billion over the next five years. The Pentagon now plans to buy 13 fewer F-35s in the next fiscal year and 179 less than planned over the five-year period through fiscal 2017.

Italy, the United Kingdom, the Netherlands, Turkey, Canada, Australia, Denmark and Norway have partnered with the United States in the development of the F-35. The Netherlands has reportedly also signaled it will buy the Lockheed Martin-built [LMT] F-35s in smaller numbers than envisioned.

Japan in December announced it would buy 42 F-35s as its next generation fighter, but has also warned it would reconsider those plans if costs were not controlled.