TEHRAN – EU foreign policy chief Catherine Ashton said on Sunday there is “no guarantee” that talks with Iran on its disputed nuclear program will lead to a comprehensive agreement.

“This interim agreement is really important but not as important as a comprehensive agreement (which is)… difficult, challenging, and there is no guarantee that we will succeed,” Ashton told a joint news conference in Tehran with Iranian Foreign Minister Mohammad Javad Zarif.

Ashton was in Iran Sunday for top-level meetings with officials who are pursuing a track of talks they hope will eventually end international pressure and suspicions over Tehran’s nuclear program.

“It is very important that with the support of the people of Iran for the work to going on by the minister and his team and with the support of international community for my work that we should aim to try to succeed,” Ashton said.

Western nations and Israel have long suspected Iran is covertly pursuing a nuclear weapons capability alongside its civilian program, charges denied by Tehran.

Zarif said Iran will only accept a deal that respects its “rights,” a reference to uranium enrichment on its soil.

“At the same time Iran finds it in its own interest to make sure that there are no ambiguities about Iran’s intentions, because we have no intention to seek nuclear weapons,” he said.

The two said they had also discussed fighting terrorism, drug trafficking, and conflicts in Afghanistan and Syria. Iran is a key ally of Syrian President Bashar Assad.

Ashton’s mainly symbolic visit comes amid a thaw in Iran’s strained relations with the West after Tehran signed a preliminary deal last November rolling back parts of its nuclear activities in return for a curbing of some Western sanctions.

Separately, Iran’s President Hassan Rouhani advocated pursuing “new relations” with European countries that for years have been at odds, alongside the United States, with Tehran over Iran’s disputed nuclear program.

“Besides ongoing nuclear talks that should be driven ahead, there are other suitable fields in which both Iran and European Union can consider push relations and cooperation ahead,” the president said in remarks quoted by his website. He suggested energy and transportation cooperation.

The breakthrough was made possible after last year’s election of Iranian President Hassan Rouhani, viewed as a relative moderate who has the ear of supreme leader Ayatollah Ali Khamenei.

The November deal has opened the way to discussions aimed at reaching a definitive accord between Iran and the five permanent members of the UN Security Council, plus Germany — the so-called P5+1.

Negotiators hope to reach final agreement by July 20, when the interim pact is due to expire.

Experts from all the parties have already met to prepare the way for the next high-level talks in Vienna on March 17, which will be followed by several others rounds until July.

Ashton, who leads the P5+1′s engagement with Iran, will later meet Rouhani, “as well as other senior officials and representatives from leading Civil Society organisations,” a brief statement from her office said.

Iranian media quoted Deputy Foreign Minister Majid Takhte Ravanchi as saying that Ashton was in Iran to discuss “bilateral ties between Iran and European Union”.

He added: “Naturally the nuclear issue will be raised too.”

The trip is the first to Iran by a European Union policy chief since 2008.

On Sunday, Ashton was scheduled to meet Rouhani, Parliament speaker Ali Larijani and Zarif.

Her trip follows official visits by top diplomats from Italy, Sweden, Belgium and Spain.

“She comes to further oil the wheels of relations with Iran,” one Tehran-based European diplomat told AFP.

“It is also a goodwill gesture from the EU.”

Human rights on agenda

The issue of human rights will also be on Ashton’s agenda, despite the potential to upset Iranian hardliners, sources close to the delegation said.

An eight-member European Parliament group visited Iran in December and met rights lawyer Nasrin Sotoudeh and film-maker Jafar Panahi, sparking criticism from conservative politicians.

MP Kazem Jalali called the meeting tantamount to “interference in Iran’s internal affairs”.

Sotoudeh was released from jail along with nearly a dozen other political prisoners last September, part of Rouhani’s charm offensive.

The United States, other Western powers and Israel have long suspected Iran of using its civil nuclear energy programme as a cover for developing atomic weapons, a charge denied by Tehran.

Zarif has repeatedly said a comprehensive nuclear deal with world powers was within the reach by July.

However, there are many outstanding sensitive issues including the scope of Iran’s enrichment programme, demands that its bunkered Fordo uranium enrichment site be closed and the Arak heavy-water reactor.

The unfinished Arak reactor is of concern to the West because Tehran could theoretically extract weapons-grade plutonium from its spent fuel if it also builds a reprocessing facility, giving it a second possible route to a nuclear bomb.

Iran refuses to close its controversial nuclear facilities, saying it could take measures to reassure the West about the peaceful nature of the plants.