The United States on Monday called for a fresh approach to sanctions for countries determined to develop nuclear weapons, saying extra incentives were needed to dissuade countries from pursuing nuclear energy technologies.

US special representative Christopher Ford called on the world to wake up to the "challenge" of a fresh nuclear arms race triggered by Iran and North Korea, at a gathering to prepare the Nuclear Non-Proliferation Treaty's next review conference in 2010.

"The international community has been struggling with proliferation challenges from Iranian and North Korean nuclear weapons ambitions that so far do not yet seem to have been abandoned," he said.

He called on countries signed up to the 1970 treaty, renewed indefinitely in 1995, to develop "swift and effective responses" to violations and minimise the "delay between detection and reaction," and called for stiffer penalties.

Ford also said better incentives should be offered for states to avoid pursuing nuclear energy technology, to ensure an interest in developing a weapons capability was minimised.

Countries who have not yet signed up to the treaty -- designed to stop the spread of weapons beyond the five main powers of the time, the United States, the Soviet Union, France, Britain and China -- criticised the refusal of the big five to commit to a calendar for disarmament themselves.

They also urged measures to bring non-aligned states including Israel into line with the treaty.

Egypt called for Israel to place all its nuclear installations under the inspections regime of the Vienna-based International Atomic Energy Agency, warning that the treaty was undermined by Israel's refusal to sign up.