TEHRAN - Iranian FM Manouchehr Mottaki said that Tehran had sent a formal protest to the United States for its "espionage" over Iran's nuclear program.

Mottaki said that a U.S. intelligence report on Iran's nuclear case earlier this week showed that "they (the Americans) have obtained the information through espionage satellite and espionage activities," the official IRNA news agency reported.

"The Foreign Ministry has sent a letter to the Swiss Embassy in Tehran the day the report was issued, as caretaker of the U.S. interests, calling for explanations on the U.S. espionage on Iran' s nuclear issue," Mottaki was quoted as saying.

He also accused the report released on Monday of claiming that Iran had a nuclear weapons program before 2003, saying "there are both facts and lies in the report of the Americans."

"Americans have raised the claim just to save face and we hope they would come to the point not to tell anything without any proof and justification," he said.

The U.S. National Intelligence Estimate (NIE), which came out on Monday, found out that Iran stopped an effort to develop nuclear weapons in the fall of 2003, but it continued to enrich uranium.

The latest report, however, said that Iran could reverse that decision and eventually produce a nuclear weapon if it wants to do so.

U.S. President George W. Bush has said there was a "great discovery" as early as August for the U.S. intelligence agencies to form the recent report, without disclosing the details.

The Washington Post has said that the new information included intercepts of conversations between Iranian military commanders.

Iranian officials have applauded the U.S. report as "proof" of the "peaceful nature" of Iran's nuclear program.

On Wednesday, President Mahmoud Ahmadinejad said the report was a "great victory for the Iranian people against the great powers."

The United States and some other Western countries have been accusing Iran of trying to develop atomic bombs under a civilian cover. But Tehran insists its nuclear program is for peaceful purposes only.

Tehran has already been imposed of two rounds U.N. Security Council sanctions over its refusal to halt uranium enrichment.