The U.S., Iran and the EU will meet in Vienna on Saturday, Jan 16, to discuss progress towards implementing Iran's nuclear deal, the U.S. State Department said, according to BBC News.

Under the deal, Iran agreed to curb its nuclear activities in exchange for sanctions relief. There is widespread speculation Iran has met the terms of the deal and the lifting of sanctions is imminent.

Verification falls to international nuclear watchdog the IAEA, which could make an announcement on Saturday.

U.S. Secretary of State John Kerry will hold talks with Iranian counterpart Javad Zarif and EU foreign policy chief Federica Mogherini in the Austrian capital.

"All parties have continued making steady progress" towards implementing the deal, the State Department said, adding it will ensure the "exclusively peaceful nature" of Iran's program.

The three-party talks are seen as a sign that implementation is near, with sources saying the IAEA could issue its report on Saturday.

"Almost all details are ironed out," one source told Reuters.

As part of the deal, Iran had to drastically reduce its number of centrifuges and dismantle a heavy-water reactor near the town of Arak, both of which could be used in creating nuclear weapons. Iran has always maintained its program is peaceful.

The July 2015 agreement was seen by some as a foreign policy landmark - Iranian President Hassan Rouhani called the deal "historic".

But opponents remain, such as some U.S. Republicans who say it does not do enough to ensure Iran cannot develop a bomb.