David Cameron has said new treaties on defence and nuclear co-operation with France were a "new chapter" in a long history of defence cooperation. Speaking alongside French President Nicolas Sarkozy, the UK PM said it would make both countries' citizens safer and would save money.

A centre will be set up in the UK to develop nuclear testing technology and another in France to carry it out. The leaders also confirmed plans for a joint army expeditionary force. After both leaders signed the two treaties, Mr Cameron said: "Today we open a new chapter in a long history of co-operation on defence and security between Britain and France."

He said it was not about a European army or about sharing nuclear weapons.

Mr Cameron said the vast bulk of Britain's military operations over the past few decades had been carried out with allies and said co-operating on testing nuclear warheads would save millions of pounds. "It is about defending our national interest. It is about practical, hard-headed co-operation between two sovereign countries."