Updated

Britain and France upped military cooperation Friday to include a joint combat drone program, aircraft carrier, and combined monitoring of nuclear weapons arsenals -- all of which could cut defense costs on both sides of the Channel.

British Prime Minister David Cameron and French President Nicolas Sarkozy set aside their disputes over the eurozone's debt crisis to agree to a raft of deals at talks in Paris.

British and French companies signed contracts worth nearly $800 million to build British nuclear reactors and build up its nuclear program with know-how from France, the world's most nuclear energy-reliant country and a major nuclear technology exporter.

"I don't think that there's been closer French-British cooperation in any time since the Second World War," Cameron told a joint news conference.

Cameron and Sarkozy talked about development of two different drone programs -- a medium-altitude long-endurance or MALE drone, and an unmanned combat air vehicle or UCAV.

Britain's BAE and France's Dassault were asked to work on the MALE, and would aim to get them operational by 2020. The two countries are also studying production of a joint UCAV with the aim to have it ready by 2030, French Defense Minister Gerard Longuet said.

With Sarkozy facing an uphill campaign for re-election amid uncertainty about who will be running France in a few months, both he and Cameron stressed the long-term nature of the agreements.

Edward Hunt of IHS Jane's Consulting said in a statement that the joint combat drone could compete for buyers with the more dominant United States and Israeli aircraft but face "many challenges."

"It would be a significant step toward the creation of a next generation combat aircraft for Europe," he said in a statement, adding "It remains to be seen whether sufficient political will can be maintained over the decade of design and testing required."

Defense Minister Longuet said the two countries had scaled back ambitions for joint work on nuclear submarines, but confirmed plans to deploy the aircraft carrier by the early 2020s. Such plans, initially announced in 2010, are aimed at trimming defense costs in both countries while maintaining aircraft carrier capability.

Britain and France also said they would look for "further collaboration in the nuclear field" after working together on jointly securing nuclear weapons stockpiles.

They will also expand the information they share to fight terrorism, and strengthen screening of traffic through the tunnel that connects the two countries under the English Channel.

The two leaders also stood firm against Syria's authoritarian leader and urged the Syrian opposition to unite so that it can get more international support to resist a deadly government crackdown.

Cameron offered careful support for Sarkozy's uphill campaign for a second term in elections in April and May.

"I wish you well," he said. But in a reference to their countries' historical enmity, Cameron said he'd stay away from any open campaigning on Sarkozy's behalf.

"I'm not altogether sure that if I made (these comments) on the campaign trail they would have the effect my friend would like them to have," Cameron said, to chuckles in the crowd.