The US returned 73 Persian artifacts to Iran after years of follow-ups by Iran's cultural heritage officials.
Iranian Foreign Ministry Spokesman Hossein Jaberi Ansari made the announcement on Sunday.
"After consultations, 73 valuable ancient artifacts belonging to the Sassanid period were returned to the Islamic Republic of Iran by the US government," he said.
"The valuable ancient cargo was delivered to the National Museum of Iran on Sunday afternoon in a ceremony attended by the foreign ministry representative," Jaberi Ansari added.
Also in 2013, Washington returned a Persian artifact to Iran after 10 years of consultations.
The 2,700-year-old Persian silver drinking cup cast in the form of a griffin was returned to Iranian President Hassan Rouhani as a token of good will while he visited the US to participate in the 68th Annual Session of the UN General Assembly in New York.
The ancient griffin had been in the US since 2003 when an art dealer smuggled it into the US.
Griffin is a legendary creature with the body, tail, and back legs of a lion; the head and wings of an eagle; and eagle talon as its front feet.
As the lion was traditionally considered the king of the animals and the eagle as the king of the birds, the griffin was thought to be a specially powerful and majestic creature.
The griffin was also thought of as king of the creatures. Griffins are known for guarding treasures and priceless assets.