The talks come amid concerns that the conflict could escalate again after the US midterm elections on Tuesday.
President Donald Trump has said the United States will not launch new attacks on Iran before the vote and that talks with the country's representatives have been productive, although he has not ruled out further military action afterwards.
Iranian Foreign Minister Abbas Araqchi said on Sunday that the purpose of the "ongoing and progressing" talks was to continue consultations with the Qatari mediators, adding Iran is prepared for "both defence and diplomacy".
Speaking to state media, Araqchi said discussions on a "two-day proposal" to reopen the Strait of Hormuz were continuing but that no final conclusion had been reached.
Qatari broadcaster al-Jazeera quoted Araqchi as saying in an interview on Saturday that Iranian and Qatari negotiators had developed a proposal to reopen the Strait of Hormuz within two days of a potential agreement with the US.
Qatar had proposed shortening the timetable in Iran's initial peace proposal from seven days to five, and that discussions were now focused on reducing it further to two days, he said.
Araqchi first presented the seven-day proposal to the US in September on the sidelines of the United Nations General Assembly in New York.
The plan called for a ceasefire across the Middle East, an end to the US naval blockade, the lifting of sanctions on Iranian oil and the release of frozen Iranian assets.
In return, Iran would reopen the Strait of Hormuz and begin negotiations with the US on a comprehensive agreement.
Iran has repeatedly said it would respond to any new attacks by striking US and Israeli targets in neighbouring countries, as the eight-month-old war continues to disrupt global oil supplies and spill over across the Middle East.
"We are doing our best in this process, and we hope that there is rationality on the other side so that they prioritise diplomacy over other paths," Araqchi said of the talks with Qatari officials.
Iran's Supreme Leader Ayatollah Mojtaba Khamenei on Saturday ordered the armed forces to be prepared for any attack while the military later announced steps to strengthen its readiness.
US Secretary of State Marco Rubio said on Saturday that Trump has not decided whether to launch new strikes against Iran but would prefer to resolve the conflict diplomatically.
Qatari mediators were in Tehran on Friday for discussions with Iranian officials before moving the talks to Doha on Saturday, an official had told Reuters.
The talks were being co-ordinated in regular contacts with the US, the official added.
with EFE
