French President Nicolas Sarkozy and Britain's Prime Minister David Cameron on Friday signed a deal on increased cooperation in the development of nuclear energy while also announcing closer defense ties.

Cameron said the British engineering firm Rolls-Royce secured a major stake in the building of four new reactors by French nuclear constructor Areva, including one at Hinkley Point in southern Britain. Other British firms are to sign deals with France's state-owned energy giant EDF as part of the project.

The two governments agreed to push ahead with the next phase of plans to build a new generation of unmanned fighter aircraft.

"When you look across the foreign policy and defense policy issues we discussed today, I don't think that there has been closer French-British cooperation than at any time since the Second World War," Cameron said.

'Appalling situation in Syria'

Britain and France are also working to strengthen a new contact group on Syria, which meets next week in Tunisia. Sarkozy and Cameron pledged to help the Syrian opposition in its struggle against Bashar Assad's regime but said conditions were not right for a foreign intervention as in Libya.

"We cannot accept that a dictator massacres his own people, but the revolution will not be brought from outside, it will rise from inside Syria, as it has done elsewhere," Sarkozy told a joint news conference.

The British Prime Minister gave his backing to Sarkozy's re-election campaign, which promises to be an uphill struggle against opposition Socialist challenger Francois Hollande.

"We'll be following your fortunes in the weeks to come on the campaign trail and I wish you luck," Cameron told Sarkozy.

db/ng (AFP, dpa)