Reuters- The chief of the U.N. atomic watchdog will hold talks on Iran's nuclear deal on Thursday for the first time with senior officials from the administration of U.S. President Donald Trump, who has branded it "the worst deal ever negotiated".

The 2015 deal between Tehran and major powers places restrictions on Iran's nuclear activities in exchange for the lifting of economic sanctions against the Islamic Republic.

The accord will be the main topic of Yukiya Amano's talks in Washington, officials involved in the dealings of the International Atomic Energy Agency (IAEA) said on Wednesday.

Trump's Secretary of State Rex Tillerson, who has called for a "full review" of the accord, is among the senior U.S. officials Amano will meet, they said.

Amano, whose agency is in charge of policing those nuclear restrictions under the deal, has publicly argued in favor of the agreement, describing it as a "net gain".

But Trump, who took office on Jan. 20, has said he wants to "police that contract so tough they (the Iranians) don't have a chance".

"IAEA Director General Amano will meet with US Secretary of State Rex Tillerson and other senior U.S. officials in Washington on Thursday, March 2," an IAEA spokesman said on Wednesday, declining to elaborate.

Amano has previously said he hopes to hold an initial discussion with Trump administration officials "as soon as possible".

The IAEA produced a quarterly report on Iran last week that said Iran's stock of enriched uranium had roughly halved after coming close to the limit of what it is allowed under the deal with major powers.

The IAEA's 35-nation Board of Governors is expected to discuss Amano's bid for re-election as director general at its quarterly meeting next week.

Amano, who is Japanese, is the only candidate and diplomats say he is all but certain of winning, though the United States is one of few countries that have yet to back him.

(Reporting by Francois Murphy; Editing by Gareth Jones)