The US has warned that the Nuclear Non-Proliferation Treaty will be rendered irrelevant if the world does not face up to the challenge posed by the nuclear programmes of North Korea and Iran.
The statement by US Assistant Secretary of State for Arms Control, Stephen Rademaker, came at a UN conference reviewing the 35-year-old treaty.
Iran denies developing weapons and is holding talks with three European countries about its nuclear fuel programme.
Germany is one of the three EU states involved.
Its Foreign Minister, Joschka Fischer, has warned Iran that any resumption of enrichment activities would end the talks.
