WASHINGTON, Jan. 30 (Xinhua) -- The U.S. government announced on Thursday that it has slapped sanctions on the Atomic Energy Organization of Iran (AEOI) and its head while renewing waivers allowing foreign companies to continue work at Iranian nuclear sites.

U.S. Treasury said on its website that it has designated the AEOI and its chief Ali Akbar Salehi.

The AEOI has "played a big role in Iran breaching its key nuclear commitments," claimed Brian Hook, U.S. special representative for Iran, at a press conference held at the State Department following the Treasury's announcement.

As a result of the designation, all property and interests in property of the designated individual and entity are blocked, and U.S. persons are generally prohibited from transacting with them.

Hook also revealed that Washington will extend its waiver for another 60 days allowing foreign companies to continue work at Iranian nuclear sites, which will make it more difficult for Tehran to develop a nuclear weapon.

The continuation of non-proliferation projects, which include the Bushehr nuclear power plant, could "constrain Iran's nuclear activities," the top official on Iran at the State Department added.

The AEOI was designated by the United States in November 2018, when the Trump administration reimposed the second batch of sanctions that had been suspended following the 2015 Iran nuclear deal.

Thursday's designation added the AEOI under the Treasury's sanctions lists for Iranian Financial Sanctions Regulations and Weapons of Mass Destruction Proliferators Sanctions Regulations.

Since its unilateral exit from the Iran nuclear deal in 2018, Washington has been mounting pressure on Tehran through a series of sanctions. Iran has maintained a tough stance and scaled back its nuclear commitments in response.

The strained U.S.-Iran tensions have escalated sharply since Qassem Soleimani, former commander of the Quds Force of Islamic Revolution Guards Corps, was killed near Baghdad International Airport by U.S. drone strikes in early January.  ■