TEHERAN/UNITED NATIONS - Iran's atomic chief said on Thursday his country expects the International Atomic Energy Agency (IAEA) to "maintain neutrality and professionalism" with regard to the nuclear talks between Teheran and Washington, according to Iran's official news agency IRNA.

President of the Atomic Energy Organization of Iran Mohammad Eslami made the remarks at a joint press conference with visiting IAEA Director General Rafael Grossi following their earlier meeting in Teheran, which aimed to resolve remaining bilateral differences.

Pointing to the IAEA's role in the nuclear talks between Iran and the United States, Eslami said the agency should refrain from expressions and actions that could be abused by those "wishing ill on" Iran.

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Eslami said both sides agreed to use the joint statement signed in March 2023 -- aimed at resolving outstanding safeguards issues -- as the basis for future cooperation. He added that deputy-level meetings would take place in Teheran in the coming days to follow up on the discussions.

Grossi, in turn, described the meeting with Eslami as "very excellent" and said he also held "deep and frank" talks on Wednesday with Iran's Foreign Minister Seyed Abbas Araghchi.

He confirmed ongoing contact with the US representative engaging in indirect negotiations over Iran's nuclear program, voicing the IAEA's willingness to act as a "bridge" between the two sides, according to the IRNA.

Grossi expressed optimism that the negotiations would lead to a positive result, while noting that the credibility of any potential nuclear deal between Iran and the United States necessitates verification by the IAEA.

The head of the UN nuclear watchdog arrived in Teheran on Wednesday evening for a two-day visit. His trip came ahead of the second round of indirect talks between Teheran and Washington, which will be held this weekend in the Italian capital Rome.

The first round of indirect talks was held in the Omani capital Muscat last week.

Iran signed a nuclear deal, formally known as the Joint Comprehensive Plan of Action, with six major countries -- Britain, China, France, Germany, Russia, and the United States -- in July 2015, accepting restrictions on its nuclear program in return for sanctions relief.

However, the United States withdrew from the deal in May 2018 and reinstated sanctions, prompting Iran to scale back some of its nuclear commitments. Efforts to revive the nuclear deal have not achieved substantial progress.

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The United Nations views the second round of negotiations between the United States and Iran this weekend as "a good sign," and hopes it will yield positive results, a UN spokesman said on Thursday.

"We very much hope that the dialogue between the United States and the Islamic Republic of Iran yields a positive outcome, which we're seeing the lowering of tensions in the Gulf region, in the Middle East, and between the two countries," Stephane Dujarric, spokesman for the UN secretary-general, said at a daily briefing.

"We understand that there will be a second round from what I've seen, I think this weekend, which in itself is a good sign," he said. "We will obviously be following it very closely."

In early March, US President Donald Trump sent a letter to Iranian leaders, proposing negotiations on Iran's nuclear program, while Iran later agreed on indirect talks.

The White House said in a statement that the discussions were "very positive and constructive." Iranian Foreign Ministry described their talks as "constructive".