But the diplomats, who declined to be named, said Iran was holding out against substantial contacts with Rice, although she and Mottaki exchanged what US officials described as pleasantries over lunch on Thursday.
Ryan Crocker, the US ambassador to Iraq, did not rule out a meeting between Rice and Mottaki.
"We are just going to take it as it goes. We will see ... what options present themselves," Crocker told reporters.
"The point from our side is not to have meetings with the Iranians. It is what can we do in Iraq and what can we do in the region to create better circumstances and a better future for the Iraqis."
While Rice and Mottaki exchanged greetings during lunch on Thursday, they did not have further contact at dinner.
Mottaki walked out of the dinner on the pretext that the female violinist entertaining the gathering was dressed too revealingly.
| Mottaki told his hosts that the lady violinist |
was scantily clad [AFP]
Mottaki's place at table had been set directly across from Rice.
When Mottaki's delegation entered the dinner and saw the arrangement, they seemed displeased, a US official who accompanied Rice said.
Mottaki immediately told his hosts that he had to excuse himself because the violinist was "scantily clad", the official said.
Sean McCormack, the US state department spokesman, said on Friday: "I don't know which woman he was afraid of, the woman in the red dress or the secretary of state."
The dinner episode on Thursday night demonstrated how hard it was to bring together the most senior diplomats of the two rival nations at this regional conference.
At the conference on Friday, Iraq's neighbours as well as ministers from the Group of Eight leading industrialised nations and the European Union were discussing how to stabilise the country.
Iraq has met its neighbours several times over the past three years and has received promises of co-operation on border security, but says armed groups are still able to smuggle fighters and weapons into the country.
Washington has accused Iran of fomenting violence in Iraq. Tehran says it does not.