Iran's new top nuclear negotiator is scheduled Tuesday to hold his first international meeting about Tehran's contentious nuclear program since his appointment — a session in Rome with the European Union's foreign policy chief.

Saeed Jalili, a little-known figure in Iranian politics, was appointed his country's chief negotiator after Ali Larijani stepped down this weekend. The relatively moderate Larijani's departure has signaled that hardline Iranian President Mahmoud Ahmadinejad may push the Islamic republic into an even more defiant position in its nuclear standoff with the West.

However, Larijani was to attend the Rome talks alongside Jalili and the E.U.'s Javier Solana, according to Iran's Foreign Ministry. The talks had been scheduled ahead of Larijani's replacement, but it was not immediately clear what role he would play Tuesday.

The U.S. and some of its allies accuse Iran of secretly trying to develop nuclear weapons and have demanded it halt uranium enrichment, a key step in the production of atomic weapons. Iran insists its program is for peaceful purposes, including generating electricity.

Before Larijani resigned, an E.U. official, who requested anonymity because of the confidential nature of the matter, told The Associated Press that the talks would focus on Tehran's refusal to heed U.N. Security Council demands for a freeze on uranium enrichment.

On Tuesday, officials in Solana's office declined to confirm the meeting's agenda, saying only that the discussions aim to push Tehran to enter formal negotiations on its nuclear program.

The United Nations has already imposed two rounds of limited sanctions over Iran's refusal to suspend enrichment. But the U.S., Russia, China, Britain, France and Germany, with E.U. support, agreed last month to delay until November any new U.N. resolution to toughen sanctions, giving Iran more time to cooperate with an investigation into past nuclear activities by the U.N.'s nuclear watchdog, the International Atomic Energy Agency.

Larijani was viewed as more moderate than Ahmadinejad, and the two often clashed over how to negotiate with the world on the nuclear issue. Larijani was seen as committed to a diplomatic solution, while Ahmadinejad is not seen as favoring talks with the West over the issue.

The president has said Iran would not negotiate over its "nuclear rights." But he also said this month that the government was prepared to answer questions from the IAEA.

It was not clear whether Larijani left his post under pressure.

Iranian government spokesman Gholam Hussein Elham gave no specific reason for the resignation other than to say Larijani wanted to focus on "other political activities." "Larijani had resigned repeatedly. Finally, the president accepted his resignation," Elham said.

Two European officials — also requesting anonymity because of the confidential nature of the matter — have told the AP in the past year that Larijani had offered his resignation several times in apparent frustration over lacking sufficient negotiating authority.

Larijani's departure was interpreted by many in Iran as giving Ahmadinejad a free hand in dictating his views to the less experienced Jalili.