(FOX NEWS) — A Qatari negotiation team is in Tehran on Friday and Saturday “to support the U.S. to reach a final deal that would end the war and address outstanding issues with Iran,” an official with knowledge of the visit told Fox News’ Chief Foreign Correspondent Trey Yingst.

The development comes after Secretary of State Marco Rubio said Friday that “slight progress” has been made towards a deal with Iran, but vowed that Tehran “can never have a nuclear weapon.”

“On the issue of Iran. The news this morning, I know it’s early still in the United States, a little later in the region, in the Middle East, but we await word on those conversations that are ongoing. There’s been some slight progress, I don’t want to exaggerate it, but there’s been a little bit of movement, and that’s good,” Rubio said during a visit to Sweden for a meeting of NATO’s foreign ministers.