“These activities did not advance beyond feasibility and scientific studies” and the acquisition of technical capabilities, the agency concluded. The efforts ended after 2009, or just as Mr. Obama was taking office and accelerating the sanctions and cybersabotage program against Iran’s nuclear facilities that ultimately brought Iranian officials to the negotiating table.

Tehran gave no substantive answers to one quarter of the dozen specific questions or documents it was asked about, leaving open the question of how much progress it had made.

The report, titled “Final Assessment of Past and Present Outstanding Issues Regarding Iran’s Nuclear Program,” will not satisfy either critics of the nuclear deal or those seeking exoneration for Iran. Instead, it draws a picture of a nation that was actively exploring the technologies, testing and components that would be needed to produce a weapon someday. However, it does not come to a conclusion about how successful that effort was.

The agency’s director, Yukiya Amano, said last week that the document would not be “black and white,” and that assessment proved correct.

Nothing in the report suggests that Iran will prevent the I.A.E.A. from monitoring its production of nuclear fuel for the next decade and a half, the crucial element of the July agreement. But Iran’s refusal to answer some of the questions also does not portend well for transparency about its activities.

At Iran’s Parchin complex, where the agency thought there had been nuclear experimental work in 2000, “extensive activities undertaken by Iran” to alter the site “seriously undermined” the agency’s ability to come to conclusions about past activities, the report said.