The US and Iran are gearing up for their first high-level talks on Tehran's nuclear programme, reported BBC.
One of the state department's most senior officials, William Burns, will be joined in Geneva by envoys from the EU, China, France, Germany and Russia.
They are expected to discuss incentives for Iran to suspend its uranium and plutonium activities with the country's top nuclear negotiator, Saeed Jalili.
The US attendance is being seen as a major shift in policy.
In 2002, President George W Bush famously named Iran as one of the countries that formed the "axis of evil".
The US has insisted that no talks would be held unless Iran suspended the enrichment of uranium, which it says could be used to produce nuclear weapons.
But with just six months left of his presidency, analysts say Mr Bush is taking a more pragmatic approach.
Secretary of State Condoleezza Rice seemed to sum up the new conciliatory mood in a speech on Friday.
She reiterated that Iran was "a difficult and dangerous state" before adding: "We have been very clear that any country can change course."
Saturday's talks will aim to find out how Iran will respond to the West's offer of economic incentives for Tehran to suspend its nuclear activities.
Iran denies any nuclear weapons plans, but is defying UN Security Council demands to halt uranium enrichment.
The talks come after weeks of rising tensions in the region.
The Iranians test-fired missiles last week, and a series of threats and counter-threats between Iran and Israel has been watched nervously in the West.
But the talks appear to have eased some of the tensions.
Reports suggest the US may even consider opening a diplomatic mission in Tehran - which would be the first such link since the US hostage crisis nearly 30 years ago.
Formal contact between the US and Iran is very rare, though the two countries held three rounds of talks in 2007 over security in Iraq.