Victoria Nuland, a spokeswoman for the U.S. State Department, announced last week that a conference to discuss the elimination of weapons of mass destruction in the Middle East was canceled.
"The United States regrets to announce that the conference cannot be convened because of present conditions in the Middle East and the fact that states in the region have not reached agreement on acceptable conditions for a conference," she said in a statement.
Ali Asghar Soltanieh, Iran's envoy to the International Atomic Energy Agency, told state-funded broadcaster Press TV the decision was a "flagrant violation" of the nuclear Non-Proliferation Treaty.
The conference was scheduled for next month in Finland. Nuland said there was a "deep conceptual gap" among regional arms control arrangements in the region. This can only be addressed, she said, by direct engagement.
British Foreign Office Minister Alistair Burt said the British government regretted that it wasn't possible to conduct a successful conference in Helsinki.
"More preparation and direct engagement between states of the region will be necessary to secure arrangements that are satisfactory to all," he said in a statement.
Nuland's announcement followed a cease-fire between Hamas and Israeli, widely believed to have a nuclear weapons program. Iran's president had said his country supports a WMD-free zone in the Middle East.