Iranian President Hassan Rouhani says the U.N. nuclear agency's decision to close the books on a decade-long probe of allegations that Tehran worked on nuclear weapons is a "big success."

Rouhani hailed the decision in a televised address Wednesday, saying it paved the way for Iran to fulfill its remaining obligations under a landmark nuclear deal with world powers. The probe had to be formally ended as part of the July 14 agreement, which will lift sanctions in return for Iran curbing its nuclear activities.

U.N. nuclear agency head Yukiya Amano has said his investigation couldn't reconstruct all the details of Iran's past activities. He said Iran worked on studies relevant to making nuclear weapons, with coordinated efforts up to 2003 tapering off into scattered activities up to 2009.