Report: Iran developing nuclear bombs

Iranian President Mahmoud Ahmadinejad slammed the IAEA and said the agency has no jurisdiction in Iran.

STORY HIGHLIGHTS

• NEW: GOP members of Congress urge White House to ratchet up economic sanctions
• NEW: Sanctions should target refined fuel supply, Iran's central bank, Rep. Mike Rogers says
• A nuclear watchdog report expresses serious concern over Iran's nuclear program
• Iranian President Mahmoud Ahmadinejad dismisses the report as fabrication

(CNN) -- The International Atomic Energy Agency issued a critical report Tuesday saying that it has "serious concerns" about Iran's nuclear program and has obtained "credible" information that the Islamic republic may be developing nuclear weapons.

The IAEA report, the most detailed to date on the Iranian program's military scope, found no evidence that Iran has made a strategic decision to actually build a bomb. But its nuclear program is more ambitious and structured, and more progress has been made than previously known.

"The agency has serious concerns regarding possible military dimensions to Iran's nuclear program," the report said. "After assessing carefully and critically the extensive information available to it, the agency finds the information to be, overall, credible. The information indicates that Iran has carried out activities relevant to the development of a nuclear explosive device."

U.S. State Department spokeswoman Victoria Nuland said the report had just arrived and refrained from commenting on details at an afternoon briefing. But a senior U.S. official called the report "a big deal."

Ahmadinejad: look at U.S. nuclear arms

Report: Iran pursuing nuclear weapons

"The report is very comprehensive, credible, quite damning, and alarming," the official said.

Read the IAEA report here

Iranian President Mahmoud Ahmadinejad slammed the report as a fabrication of facts aimed at satisfying U.S. allegations about Iran's nuclear program.

Ahmadinejad essentially called Yukiya Amano, the director general of the IAEA, a U.S. puppet and said the United Nations agency has no jurisdiction in Iran.

"The Americans have fabricated a stack of papers and he keeps speaking about them," he said on state-run Press TV. "Why don't you do a report on the U.S. nuclear program and its allies? Present a report on the thousands of U.S. military bases where Washington has nuclear arms that threaten global security."