US Secretary of State Hillary Clinton voiced hope Tuesday the United States and Iran will find a way to open a direct dialogue and "develop a better understanding of one another."

However, Clinton reiterated US opposition to Iran's nuclear ambitions and said a US missile shield in the Czech Republic and Poland would be a deterrent if it is proven technically and financially feasible and Iran remains a threat.

"We still persist in our view that Iran should not obtain a nuclear weapon," Clinton told reporters during a visit by Czech Foreign Minister Karel Schwarzenberg.

She added that would be "a very unfortunate course for them to pursue," referring to US fears that Iran's uranium enrichment program masks efforts to build a nuclear bomb.

Iran says its program is peaceful.

"And we hope that there will be opportunities in the future for us to develop a better understanding of one another and to work out a way of talking that would produce positive results for the people of Iran," Clinton said.

She was reacting to comments in Tehran by President Mahmoud Ahmadinejad who said Iran is prepared to talk to the United States in an atmosphere of equality and mutual respect after three decades of severed ties.

US President Barack Obama on Monday said he hoped to create the conditions for face-to-face dialogue in the months ahead. The previous administration of George W. Bush shied away from direct talks.

Obama has also left the door open to abandoning the Bush team's plans to deploy missile interceptors in Poland and a radar in the Czech Republic to guard against Iranian missiles.

With Schwarzenberg by her side, Clinton said technical problems and costs could delay or derail plans, while Iran could obviate the need for a shield one day.

"If we are able to see a change in behavior on the part of the Iranians with respect to what we believe to be their pursuit of nuclear weapons ... then ... we will reconsider where we stand," Clinton said.

"But we are a long, long way from seeing such evidence of any behavior change," said Clinton who stressed the deterrent effect from a missile shield.

Schwarzenberg added: "As with Iran, as to other dangers in the world, we need to stick together."

Czech Prime Minister Mirek Topolanek has backed the project since he came to power in 2006 but several Czech politicians are worried the new administration may re-think the plan.

A majority of the Czech people oppose the shield.

To take effect, the shield project must be ratified by both houses of the Czech parliament and signed by the president. The upper house Senate has already backed the project.

Russia is vehemently opposed to the shield as a strategic threat.