Obama warns of nuclear terrorism

US President Barack Obama has cited the possibility of a terrorist organisation obtaining a nuclear weapon as the biggest threat to the country’s security.



Speaking on the eve of a nuclear security summit in Washington, Mr. Obama said leaders from 40 states should focus on how to secure nuclear material.



He says groups like al-Qaeda will not hesitate to use nuclear devices.



Neither North Korea nor Iran, two states with disputed nuclear ambitions, have been invited to the summit.



The two countries are viewed by the US as violators of the non-proliferation agreement.



However, the leaders of nuclear states like India, China and Pakistan are among those travelling to Washington for the biggest gathering of world leaders in the US capital in decades.



Leaders or other representatives of 47 states are attending the summit.