THE HAGUE - US President Barack Obama gathers world leaders in The Hague on Monday to seek ways of preventing a terrorist nuclear attack, at a key summit that risks being overshadowed by the explosive Ukraine crisis.
Over 50 leaders are to attend the Nuclear Security Summit (NSS) at the behest of Obama, who has called a simultaneous meeting of the Group of Seven top economies to discuss further sanctions against Russia.
G7 leaders from Britain, Canada, France, Germany, Italy, Japan and the US will likely meet on Monday, diplomats said, leaving Tuesday free to discuss securing the world's stocks of nuclear material to prevent a group like Al-Qaeda acquiring a nuclear or so-called 'dirty' bomb of conventional explosives wrapped in radioactive material.
Obama has made nuclear security and cutting nuclear weapon stocks a centrepiece of his political legacy, saying in 2009 that nuclear terrorism was "the most immediate and extreme threat to global security."
The Nobel Peace Prize winner set out to secure all vulnerable nuclear material worldwide within four years, with nuclear security summits held in Washington in 2010 and Seoul in 2012. Obama will host a final summit in 2016.
One of the summit's aims is to get countries to give up their stocks of highly-enriched uranium and plutonium, which can be used to make an atomic bomb, in exchange for less dangerous low-enriched uranium.
"A nuclear terrorist event would impact the entire world so it's a global problem that requires a global solution, and the NSS has brought this problem the appropriate political attention," Kelsey Davenport, Non-proliferation analyst at the Arms Control Association, told AFP.
The Dutch hosts, who have mounted an unprecedented security operation around the summit, with much of the sleepy Hague suburb of Scheveningen locked down, have said the summit has three aims: reducing the amount of nuclear material, protecting radioactive material and strengthening international cooperation on nuclear security.
Almost every country has radioactive material that could be used in a "dirty" bomb.
"You might not have a nuclear reactor in your back yard, but you probably have a hospital, with different (radiological) sources, for cancer treatment and sterilisation, I don't think people realise how close to home some of this hits," Michelle Cann, Senior Budget and Policy Analyst at the Partnership for Global Security, told AFP.
"The impact would be so widespread, in so many different areas. That's what makes it so important to act preventively," said Cann.