While keeping their options open, the United States and European Union have signaled that talks with Iran over its nuclear programme could resume, for the first time in more than a year, after Tehran dropped its pre-conditions to a dialogue.
Stopping short of calling it a diplomatic breakthrough, top US and EU officials expressed cautious optimism over prospects that Iran may be willing to engage major powers in new talks, but emphasised that any dialogue should be focused on the nuclear issue.
"It's good to see that the letter has arrived and that there is a potential possibility that Iran may be ready to start talks," European Union High Representative for foreign policy Catherine Ashton told reporters at a joint media availability with US Secretary of State Hillary Clinton
Ashton said she received a letter from Iran in response to her letter in October last year. "We are consulting colleagues and analysing closely what this letter would mean."
Clinton said international community has been looking to Iran to demonstrate it is prepared to come to the table in a serious and constructive way.
The new hope of negotiations comes after weeks of bluster including ominous threats of military action in the Persian Gulf and terror strikes on Israeli diplomats in India, Thailand and Georgia that Tel Aviv has blamed on Iran.
Clinton said: "We have been reviewing Iran's proposal to resume talks on its nuclear activities and consulting closely between us and with our other P-5 plus one partners. This response from the Iranian government is one we've been waiting for, and if we do proceed, it will have to be a sustained effort that can produce results."
Noting that they are evaluating the response, Clinton said there is unity within P-5 plus one on the Iran issue.
"It takes time to consult and to do so in a thorough manner. So we need to give time to our partners in the P-5 plus one process to do their own evaluation," she said.
"We have been clear about two things that I want to stress. First, as outlined in Cathy's October letter to Iran, any conversation with Iran has to begin with the discussion of its nuclear program," she said.
"Iran's response to Cathy's letter does appear to acknowledge and accept that. And second, we must be assured that if we make a decision to go forward, we see a sustained effort by Iran to come to the table, to work until we have reached an outcome that has Iran coming back into compliance with their international obligations," Clinton said.
Speaking on crisis in Syria, Clinton said the recent UN General Assembly vote reflects that the international community is against the Assad regime.
"We have marshalled the great weight of international opinion against the Assad regime. The vote yesterday in the General Assembly was overwhelming," Clinton said.
"In the face of this global condemnation, the regime in Damascus, however, appears to be escalating its assaults on civilians," she said.
"Those who are suffering cannot get access to the humanitarian assistance they need and deserve. So we will keep working to pressure and isolate the regime, to support the opposition and to provide relief to the people of Syria," she said.
Clinton said she will be attending the Friends of Syria conference in Tunisia next week, where a number of nations will work to intensify pressure on the regime and to mobilise the humanitarian relief that is needed.
"We also hope to coordinate efforts to enable a Syrian-led transition before the regime's actions tear the country apart. We're looking for an inclusive, democratic process. Ultimately our shared values between the US and the EU are the bedrock of our cooperation, and we are promoting those values together," Clinton said.
"I do want the people of Syria to understand and believe that there are tens of millions of people around the world who are seized with the terrible situation they find themselves in. We have not been deterred by the vetoes in the Security Council," she said.
"We are moving forward with the Friends of Syria. They are not being abandoned," she added.
Ashton said the situation in Syria is a cause for enormous concern.
"We feel extremely worried about the level of violence and terror that is happening within that country. We've been very clear that President Assad should stand aside and should enable a process that would bring the people of Syria together, all of them, an inclusive process that could take the country forward," she said.