In a strongly-worded statement, the leaders of the world's most powerful nations called the uncurbed spread of armaments and international terrorism "the pre-eminent threat to international security".

To this end a G8-wide Counter-Terrorism Action Group would be formed to share information and coordinate responses, they said.

Among other measures announced at the gathering in the French lakeside resort of Evian, the leaders pledged to crack down on the spread of low-level radioactive sources which could be used to make so-called "dirty bombs".

New curbs were also announced on the sale of hand-held anti-aircraft missiles.

North Korea, which caused global alarm late last year when it admitted the existence of a nuclear weapons program, was warned to mend its ways.

"We strongly urge North Korea to visibly, verifiably and irreversibly dismantle any nuclear weapons programs, a fundamental step to facilitate a comprehensive and peaceful solution," the G8 leaders said.

They said Pyongyang's failure to abide by International Atomic Energy Agency safeguards constituted a "clear breach of North Korea's international obligations."

With respect to Iran, the leaders said they would "not ignore the proliferation implications of Iran's advanced nuclear program," urging "full compliance with its obligation" under the nuclear Non-Proliferation Treaty.

Tehran has come under increasing international pressure to allow access for weapons inspectors at its Russian-built Bushehr plant, which is due to go on line at the end of the year, amid growing concern it might be used to produce nuclear arms material.

The G8 leaders had shown "strong unity" in demanding Iran comply with the demands, French President Jacques Chirac's spokeswoman Catherine Colonna said later.

However later Monday Russia said it was close to signing a deal that would remove spent fuel waste from the plant, which could be used to make weapons, out of Iran.

US President George W. Bush last year branded Iran and North Korea -- along with Iraq -- as part of an "axis of evil" that he said was developing weapons of mass destruction and sponsoring terroris,

The G8 nations -- which pledged at their last summit in Canada to spend 20 billion dollars over the next decade curbing weapons proliferation -- promised to set up national registers to control the movements of low-grade radioactive materials, such as x-ray machines.

"Certain poorly-protected (radiation) sources pose a real threat" because they could be used to make a dirty bomb, the declaration cautioned.

Measures were also promised to halt the spread of hand-held surface-to-air missile launchers known as Man-Portable Air Defence Systems (Manpads), including a ban on sales other than to other countries, in a bid to prevent them being used be terrorists.

In November two missiles thought to have been fired from such a weapon narrowly missed an Israeli charter flight which that had just taken off from Mombasa, Kenya, with 261 passengers aboard.

Additionally, the declaration pledged new measures on the "biometric testing" of travellers, by which identities can be confirmed through the examination of physical characteristics such as irises.

WAR.WIRE