Washington, DC - The Obama administration is cautiously optimistic about the overtures which Iran's new president is making to the international community.
However, it is refusing to lower its guard on the matter of Iran's nuclear program – which the US has long believed is meant to develop weapons, not power reactors.
First, the overtures: In an interview with the US TV network NBC on Wednesday, President Hassan Rouhani said he welcomed a letter of congratulations from US President Barack Obama over his recent election victory.
Rouhani repeated the Iranians' longtime assertion that they are not trying to build nuclear weapons, and then said he was fully empowered to negotiate with the US and others about the program's future.
Iran's foreign minister also discussed the controversy during a meeting with UN Secretary General Ban Ki-Moon – telling reporters afterwards that Tehran values whatever input the UN can provide in resolving the crisis.
Does all this mean that US-Iranian relations are now on the upswing? Not necessarily.
John Kerry, the US secretary of state, said on Thursday: "Rouhani’s comments have been very positive, but everything needs to be put to the test."
White House Secretary Jay Carney said: "It's important when we're talking about this incredibly serious matter of a nuclear weapons program that we not just take Iran's words for it, that we back it up and see if it's real."
And allies such as Israel are keen to see Iran held to account.
From the US perspective, that means a resumption of full talks between the five permanent UN Security Council members plus Germany, known as P5+1, comprehensive inspections, and a verifiable commitment from Iran to abandon whatever dreams it has of becoming a nuclear power.
What's more, the US-led economic sanctions regime is still fully in place, with no hint of easing any time soon.
But the feelers have been extended – and the Obama administration is not ruling out the possibility that the US president and his Iranian counterpart might do more than exchange letters soon.