EU foreign policy chief Javier Solana began talks here Tuesday with Iran's new nuclear pointman Saeed Jalili, who vowed to pursue negotiations "with strength."
It was Solana's first sit-down with Jalili, whose appointment has been viewed as possibly signalling a tougher Iranian stance in the long-running dispute over its contested nuclear programme.
"We will continue the nuclear discussions with strength," Jalili told Iranian state media in Rome before the talks began.
"The nuclear issue is an issue on which there is a consensus and national harmony," he said. "Many efforts have been made in this field and God willing this process will continue with strength."
Jalili, a hardliner close to the Iranian president, took over as chief nuclear negotiator on Sunday after the sudden resignation of the conservative but pragmatic Ali Larijani.
Larijani had fallen out with Ahmadinejad over the handling of the nuclear row, but still accompanied Jalili to Rome and insisted that a new negotiator did not mean a new policy.
"Even if there is a change in president, the policy will not change," he said.
While there is little expectation of a breakthrough in Rome, the talks will be carefully monitored for any sign that Jalili intends to take a tougher line.
"We are going to see what attitude they arrive in Rome with" and whether Larijani's departure "implies a change of stance one way or the other," said Solana's spokeswoman, Cristina Gallach.
Larijani's replacement has not passed without criticism in Iran where almost 200 MPs signed a letter on Tuesday expressing appreciation of his work on the nuclear issue.
"The resignation of Larijani shows that the circle of people in the executive is shrinking and its capacity for using the services of past officials is falling," said former Iranian vice president Mohammad Hashemi.
Larijani was believed to support a more moderate line in the nuclear standoff -- at least over the presentation of policy.
Mark Fitzpatrick, director of the Non-Proliferation Programme at the International Institute for Strategic Studies, said Jalili's appointment could signal a step backwards.
"I think it makes it harder to strike a deal, because there is nobody to negotiate with who has some pragmatic inclination," Fitzpatrick said.
Just hours before the Rome talks began, US President George W. Bush warned that Iran could develop an intercontinental ballistic missile able to reach the United States and all of Europe before 2015.
Last week, Bush suggested that a nuclear-equipped Iran evoked the threat of "World War III".
Solana, negotiating on behalf of major powers Britain, France, Germany, China, Russia and the United States, will renew an offer first made in June last year of an extensive package of political and economic incentives in exchange for Iran giving up uranium enrichment.
"It's a case of finding out once more whether there is the possibility of starting negotiations" on the offer, Gallach said.
She argued that the package "gives Iran all it requires for a civil nuclear programme ... and would open the way for a political relationship which would bring Iran out of its current isolation."
The United States says Iran's enrichment operations are aimed at fuelling a covert nuclear weapons programme, while Iran insists it wants only to generate energy and has every right to the full nuclear fuel cycle.
Earlier Tuesday, Iranian President Mahmoud Ahmadinejad cut short a visit to Armenia and returned home "for urgent reasons," according to Armenian presidential spokesman Viktor Sogomonian.
A diplomatic source in Yerevan said the president's abrupt departure was prompted by concern over the "internal political situation" in Iran and the negotiations in Rome.
Solana and Jalili were scheduled to brief reporters after their meeting.
