GENEVA, Oct. 1 (Xinhua) -- U.S. and Iranian officials met bilaterally on Iran's nuclear program in Geneva on Thursday, a U.S. State Department spokesperson confirmed.

    The bilateral meeting was held between U.S. Under Secretary of State William Burns and Iran's chief nuclear negotiator Saeed Jalili on the margins of the Geneva talks, which also involve senior diplomats from Britain, France, Russia, China and Germany, Robert Wood told reporters.

    But Wood refused to reveal more details about the discussion between Burns and Jalili.

    This is the most high-level U.S.-Iran contact since the two countries severed diplomatic relations following the 1979 Islamic Revolution in Iran.

    The Geneva talks, which are expected to last for a full day behind closed doors, are part of the international efforts to settle a long-running standoff over Iran's nuclear program.

    The United States and other Western powers have long suspected Iran's nuclear program is aimed at producing nuclear weapon material, but Tehran argues that it has no intention to make nuclear weapons and that its atomic drive is only for peaceful purposes.

    This is the first such high-level meeting between Iran and the six countries since a similar session in July 2008 ended without substantive progress.

    It is also the first time that the United States is participating fully at the talks with Iran -- Washington was present at the 2008 talks only as an observer.