Iran says it will take part in a planned security conference in Iraq, to be attended by the US, if it is "in Iraq's best interests".
The US has accused Iran of adding to Iraq's sectarian strife
Senior Iranian official Ali Larijani said Tehran was reviewing the proposal but that it supported "solving problems of Iraq by all means".
Iraq's PM Nouri al-Maliki has announced the meeting will be on 10 March.
The US says it will attend the talks that include Syria and Iran - accused by the US of fuelling strife in Iraq.
Mr Maliki's office said he had sent out invitations to the five permanent UN Security Council members, the Arab League, the Organisation of the Islamic Conference, Egypt and Iraq's neighbouring countries, including Syria and Iran.
A statement from the office read: "We hope the meeting will bring political backing for the national unity government in providing security and stability."
Mr Larijani, head of Iran's Supreme National Security Council, said: "We are reviewing the proposal. We support solving problems of Iraq by all means and we will attend the conference if it is expedient.
"We believe Iraq's security is related to all its neighbouring countries and they have to help settle the situation."
Iran will attend if it is "expedient", said Mr Larijani
The BBC's Pam O'Toole says his words are relatively positive but fall short of an outright acceptance and this may be because Iran is trying to work out what the US agenda is.
She says some Iranians will remember how Tehran co-operated in a summit on Afghanistan in 2001 only to be denounced shortly afterwards by President George W Bush as being part of "the axis of evil".
The US has been stepping up pressure on Iran recently, accusing it of supplying Shia militants in Iraq with weapons to attack US forces, an allegation Iran rejected as "baseless propaganda".
But the Bush administration has been under pressure in Congress and from the findings of the bipartisan Iraq Study Group to include Syria and Iran in dialogue to stabilise Iraq.
Our correspondent says Iran may feel its inclusion in the guest list is at least a recognition from Washington that it cannot solve Iraq's problems without Tehran's co-operation.
The official Syrian news agency, Sana, has confirmed Damascus officials will attend the meeting.
Iraqi Deputy Foreign Minister Labid Abawi told Associated Press he saw no sign that any country would refuse the invitation.
The last time there were even informal talks between the US and Iran was in late 2004 when then US Secretary of State Colin Powell and his Iranian counterpart, Kamal Kharrazi, sat next to each other at dinner in Sharm el-Sheikh, Egypt.
US Secretary of State Condoleezza Rice said on Tuesday: "We hope that all governments seize this opportunity to improve their relations with Iraq and to work for peace and stability in the region."
Asked about face-to-face meetings with other delegates, state department spokesman Sean McCormack would not "exclude any particular interaction".
The conference is likely to be at non-ministerial level.
However, Ms Rice said there could then be a second meeting in April of ministers from countries attending the first, plus others in the G8 grouping.
BBC diplomatic correspondent Jonathan Marcus says the latest developments show, in a small way, that Ms Rice has trumped Vice-President Dick Cheney and that diplomacy is reasserting itself in Washington.