Iran's new nuclear negotiator has said his country will continue nuclear discussions "with strength".
Mr Solana (C) held talks with both Mr Jalili (R) and Mr Larijani (L)
Saeed Jalili, who was in Rome for talks with EU envoy Javier Solana, said there was a consensus on the issue in Iran.
Mr Jalili said after the meeting Iran sees nuclear talks with the EU as a way of improving relations. He added Tehran supported "dialogue and negotiation".
Mr Solana said the meeting with Mr Jalili was "constructive" and that more talks were planned for November.
Mr Jalili's predecessor - who resigned on Saturday - backed him, saying Iran's nuclear policy would not change.
Ali Larijani resigned over reported disagreements with President Mahmoud Ahmadinejad. More than 180 Iranian MPs have signed a letter praising him.
The resignation revealed growing splits on how to proceed on the nuclear issue, says the BBC's Jon Leyne in Tehran.
But in his first public comments since taking over the position, Iran's new representative denied there were splits.
"We will continue the nuclear discussions with strength. The nuclear issue is an issue on which there is a consensus of national harmony," Mr Jalili was reported as saying in Rome ahead of the talks with Mr Solana.
Mr Larijani, who accompanied Mr Jalili to Rome, said: "Iran's nuclear policies are stable and they don't change with a change in the secretary of the council or even presidents."
Western countries suspect Iran of trying to build nuclear weapons but Tehran says its programme is peaceful.
Mr Larijani is said to disagree with President Ahmadinejad
UK Prime Minister Gordon Brown said on Tuesday that he would seek to tighten sanctions aimed at discouraging Iran's nuclear programme.
"We will work through the United Nations to achieve this. We are prepared also to have tougher European sanctions," Mr Brown said after meeting Israeli Prime Minister Ehud Olmert in London.
"We want to make it clear that we do not support the nuclear ambitions of [Iran]," he said.
On Monday, 183 MPs signed a letter praising Mr Larijani's performance as a nuclear negotiator after he was replaced by Mr Jalili, the deputy foreign minister and a close ally of President Ahmadinejad.
The letter came as former Foreign Minister Ali Akbar Velayati - now senior foreign policy adviser to Supreme Leader Ayatollah Ali Khamenei - said the resignation had come at the wrong time.
Mr Ahmadinejad accepted Mr Larijani's resignation, which had been tendered repeatedly, on Saturday.
Mr Larijani accompanied his successor to the Rome talks as the representative of Ayatollah Khamenei.
Iran is developing the technology to enrich uranium on an industrial scale. The enriched uranium can be used as fuel in a nuclear power station.
Some Western countries, led by the US, fear Iran will further process the enriched uranium for use in nuclear weapons.