France’s Ministry of Foreign Affairs and spokespeople for newly-elected president François Hollande have both stressed that Rocard’s visit is completely private and that he was not dispatched as a representative of France.
A European embargo on Iranian oil, an idea pushed determinedly by France during Nicolas Sarkozy’s presidency, is due to take effect on 1 July.
Some of Nicolas Sarkozy’s political allies have criticised the timing of Rocard’s visit.
Rocard had talks with Iranian Foreign Minister Ali Akbar Salehi and the secretary of Iran's Supreme National Security Council Saeed Jalili, who is also Tehran's chief nuclear negotiator.
"Salehi assured me that Iran was ready to take forward steps," at the May 23 Baghdad talks with major world powers, which is aimed at ending the crisis over Iran's controversial nuclear enrichment programme, Rocard said.
He said that Aladin Borujerdi, the head of Iranian parliament's foreign policy commission, had also told him that Tehran was ready to "reset the counters to zero" in the Baghdad talks.
Iran and the UN nuclear agency on Monday went into two days of talks in Vienna ahead of the crucial dialogue in Baghdad.
The meeting between Iran's envoy to the International Atomic Energy Agency, Ali
Asghar Soltanieh, and chief inspector Hermann Nackaerts was aimed at clarifying suspicions Tehran had done nuclear weapons research.
Rocard stressed to the Iranian officials that Paris "has not changed its firm position" on the nuclear issue since the May 6 election of socialist Francois Hollande.
"I insisted that France will remain totally supportive of its partners in the negotiations" between Iran and the group of 5+1 (United States, Russia, China, France, Britain and Germany) said Rocard.
The Baghdad dialogue comes after Iran and the world powers resumed negotiations over the suspected atomic drive of Tehran in Istanbul in April after more than a year of hiatus.
Western nations suspect that Iran is seeking a weapons capability masked by its civilian nuclear programme. Tehran vehemently denies the charge.