Iranian Foreign Minister Mohammad Javad Zarif said a ministerial meeting with the P5+1 countries would likely be necessary following talks in Geneva this week aimed at reaching accord over Tehran's nuclear programme.
"I hope that we will be able to reach a roadmap by Wednesday but... it will probably be necessary to have a new ministerial meeting," Zarif wrote on his Facebook page late on Sunday.
The talks in Geneva on Tuesday and Wednesday will be between Iran's Deputy Foreign Minister Abbas Araqchi and his counterparts from the P5+1 group -- the US, France, Britain, Russia, China and Germany.
A first ministerial meeting took place last September on the sidelines of a United Nations General Assembly.
Zarif will take part in the opening sessions in Geneva but Araqchi will lead the Iranian delegation during the talks.
Zarif wrote on his Facebook page, however, that "If necessary, I will also speak".
"We want to change the approach of the past six years which have given no results," Zarif wrote.
Araqchi, speaking to the state broadcaster on Sunday, said the "plan that will be presented by Zarif to the P5+1 countries during the opening session... has been prepared so that there can be no pretext to refuse it".
He did not give any further details on the plan but said uranium enrichment was a "red line" for the Islamic republic.
"We will negotiate about the volume, levels and the methods of enrichment but shipping out the (enriched) material is a red line for Iran," Araqchi said.
Iran currently has 6,774 kilograms of low-enriched uranium, and nearly 186 kilograms of material enriched to 20 percent, as well as 187 kilograms of the 20 percent material converted to uranium oxide for use in fuel plates.
It also possesses some 187 kilograms of the 20 percent material converted to uranium oxide for use in fuel plates.
Iran insists that its nuclear programme is solely for peaceful purposes, although Western powers and Israel say it is aimed at developing an atomic bomb, which Tehran has repeatedly denied.