He said the report was submitted late Friday to the Vienna headquarters of the International Atomic Energy Agency, in comments confirmed by the IAEA.
The report follows one by Iran last October that failed to live up to Iranian promises to fully disclose its nuclear activities.
The United States claims Iran is hiding a program to build the bomb and has called for the IAEA to refer it to the UN Security Council for possible sanctions.
But diplomats said the new declaration had come too late for the IAEA to be able to evaluate it fully before a meeting of the agency's 35-nation board of governors in mid-June.
The IAEA will not be able to make a final finding on Iran at this June 14 meeting due to delays by Tehran in allowing international inspections and disclosing its nuclear activities, diplomats said.
"This is ironic since the Iranians are the ones who want the file on them to be closed," said a diplomat close to the IAEA and who asked not to be named.
IAEA spokesman Mark Gwozdecky said the Iranians had filed their report under an additional protocol to the nuclear Non-Proliferation Treatythat mandates tougher inspections.
"This declaration should broader provide information about Iran's nuclear and nuclear-related activities and will facilitate the IAEA's assessment of the correctness and completeness of information already provided by Iran on its past and present nuclear activities," Gwozdecky said.
Hosseini said that even though the Iranian parliament has not yet ratified the protocol which Iran signed on December 18, Iran had "decided to apply it voluntarily as a confidence-building measure" and was filing the report that is required within six months under the protocol.
He said the declaration gave "information related to our 10-year research and development program with regard to the nuclear fuel cycle and related technologies."
Hosseini said an Iranian technical delegation might visit Vienna in the coming week to talk with IAEA officials.
Iran claims it is embarked on a project solely to develop nuclear energy for peaceful electricity production and that it seeks to enrich uranium as fuel for reactors.
Hosseini did not provide details of whether Iran had answered such key IAEA questions as the extent of technology it may have developed with sophisticated P2 centrifuges that can be used to enrich uranium to bomb-grade levels.
He said the report had provided information on "the capacity of uranium mines" in Iran, and, regarding nuclear installations, given "a description of each building and places in sites that have been declared to the agency" as well as "information related to past activities."
IAEA inspectors see a pattern of radiation contamination in Iran which could indicate attempts to enrich uranium to bomb-grade level, diplomats close to the agency have told AFP.
IAEA inspectors have reported two such concentrations -- at a Kalaye Electric Company workshop in Tehran and at the Natanz pilot fuel enrichment plant 250 kilometres (150 miles) south of the Iranian capital.
Diplomats have confirmed to AFP that other sites have been found.
But they have not provided details, and one diplomat downplayed the possibility that the IAEA has found a "smoking gun" to prove Iran is secretly developing nuclear weapons.
Iran claims the contamination from particles of enriched uranium is from equipment it imported through an international black market.
IAEA inspectors are completing months of investigations in order to prepare a report for the June board meeting.
Iranian Foreign Minister Kamal Kharazi has said Tehran expected the IAEA probe to be completed by June.
But an earlier delay to a crucial round of inspections in March "threw us out of sequence," an official close to the IAEA said.
Iran delayed inspections after the IAEA board in March condemned the country for failing to report key activities, particularly its acquiring of blueprints for the sophisticated centrifuges.