WASHINGTON Democratic presidential contenders Bill Richardson and Hillary Clinton said on Wednesday the United States should keep talking to Iran as part of an international diplomatic effort to persuade Tehran to abandon its nuclear weapons program.
Richardson, the governor of New Mexico and a former ambassador to the United Nations, said the United States should stop threatening Tehran and begin talks with no preconditions on its nuclear ambitions.
"Talking without preconditions does not mean backing off one inch over fundamental objectives, such as ensuring that Iran never acquires nuclear weapons," Richardson said in a speech to the Center for National Policy.
In a separate speech, Clinton said the Bush administration, which has had minimal direct dealings with Iran, seems reluctant to continue engaging Tehran. She faulted the administration for giving Iran "six years of the silent treatment."
"I think we should keep talking," the New York senator said at the Center for a New American Security, a new think tank.
The biggest U.S. challenge on the international front was "restoring our leadership by once again valuing alliances, respecting our values, and understanding that American strength is more than just the show of force," she said.
Iran has defied U.N. Security Council demands to halt all uranium enrichment activities, which can produce material for a nuclear weapon. The United States says Tehran's nuclear program is aimed at building bombs, but Tehran says it is designed to produce electricity so it can export more oil and gas.
The Bush administration has refused to rule out military options to halt Iran's nuclear weapon development. World powers have insisted Tehran stop enriching uranium as a precondition for formal negotiations on trade and other incentives.
"The message to the Iranians must be clear: work with the international community and you will be safe and prosperous. Continue to defy the international community and you will suffer economically and politically damaging international sanctions," Richardson said.
Recent U.S. talks with Iran on concerns about Iraq and Afghanistan were a step in the right direction, he said, proposing "broad, bilateral, unconditional negotiations with Iran -- with all subjects open to discussion."
Most Democratic contenders in the race to succeed President George W. Bush in 2008 have urged direct talks with Tehran. In a recent debate, some Republican presidential contenders said all options including nuclear strikes should be on the table.
Clinton leads the Democratic field in national opinion polls, while Richardson has been trying to break into a top tier that also includes Sen. Barack Obama of Illinois and former Sen. John Edwards of North Carolina.
(Additional reporting by Carol Giacomo)