London (AP) - Europe's two nuclear-armed powers will strike a deal Tuesday for unprecedented cooperation on defense -- sharing warhead testing facilities and aircraft carriers to preserve their military might in an era of austerity.
British Prime Minister David Cameron and French President Nicolas Sarkozy were holding talks in London and pledging a new era of collaboration -- seeking to spread the hefty costs of defense as their economies recover from the global financial crisis.
The continent's two largest military powers will also announce the formation of a joint expeditionary force -- a pool of about 5,000 troops able to deploy together at short notice on peacekeeping, rescue or combat missions.
Senior British officials said the two countries will also agree to some shared use of each other's aircraft carriers, as defense cuts mean both nations will have only one carrier each in the future.
Fighter jets will be able to land on carriers from either country -- initially during training -- providing cover when one nation has its carrier in dock for maintenance.
Cameron told a Cabinet meeting that the nuclear testing plan alone would save "hundreds of millions of pounds." However, officials declined to estimate how much overall the defense agreements will save from budgets.
Last month, Britain announced an 8 percent cut to the annual 37 billion pound ($59 billion) defense budget over four years and confirmed that 17,000 troops, a fleet of jets and an aging aircraft carrier would all be lost to cuts.
The two nations will cooperate on the development of new unmanned aerial drones, satellite communications and submarine technology. London and Paris are also likely to strengthen intelligence sharing under the deal, officials said.
"There are many areas where we can work together and enhance our capabilities -- and save money at the same time," Cameron told lawmakers on Monday.
Under the nuclear warhead plan, Britain and France will share equipment and facilities at the U.K. Atomic Weapons Establishment in Aldermaston in southern England, and the Valduc facility, close to Dijon, southeast of Paris.
The French laboratory will host British defense scientists to carry out tests on their country's nuclear warhead stockpile -- soon to be cut to 120. In return, French officials will be stationed at the U.K.'s facility to work on nuclear test technology.
British officials acknowledged the deal would involve closer cooperation than ever before on their nuclear weapons program with the French, but insisted they would not divulge nuclear secrets.
Both nations will retain "full sovereignty over their results," in tests, the French president's office said.
In a letter published Tuesday in Britain's Daily Telegraph and France's Le Figaro, senior retired security officials -- including former armed forces chief Charles Guthrie and ex-MI6 spy agency chief Richard Dearlove -- urged leaders to consider an eventual joint nuclear weapons program.
"Cooperation on warhead maintenance would be an essential first step towards a possible joint deterrent in the future," the letter said.
Cameron said the deal would not compromise the ability of either country to carry out military operations alone in the future. "Partnership, yes. But giving away sovereignty? No," Cameron told the House of Commons.
A combined pool of British and French troops will be able to carry out missions from next year and will also conduct training exercises in 2011. The pool is likely to include special forces.
Other allies welcomed the deal. The U.S. said compatibility of equipment -- such as aircraft carriers -- was a key NATO goal. "Such increased bilateral defense cooperation among NATO allies will make us all more secure," said a spokesman for the U.S. embassy in London, on customary condition of anonymity.
Though France and Britain worked closely in Bosnia and Kosovo, Paris opposed the 2003 U.S.-led invasion of Iraq and only rejoined the NATO command structure in 2009 after an absence of about 40 years.
Associated Press writer Elaine Ganley in Paris contributed to this report.