U.S. Secretary of State Hillary Clinton says Iran must respond soon to the “serious questions” raised in a U.N. report about its nuclear program.

Earlier this week, the International Atomic Energy Agency said it had “credible” information that Iran has engaged in activities aimed towards the development of nuclear weapons. Tehran maintains that its nuclear program is peaceful.

Clinton said Friday that Tehran has a “long history of deception and denial” regarding its nuclear program. She also said the U.S. will continue to work closely with its allies on exploring ways to increase pressure on Iran. She made the comments at the Asia Pacific Economic Cooperation summit in Honolulu.

Also Friday, the IAEA revealed more information about its findings on Iran during a technical presentation to member states. News reports say the U.N. nuclear watchdog agency showed satellite images and letters to bolster its case that there are military dimensions to Iran's nuclear program.

However, Tehran's IAEA envoy, Ali Asghar Soltanieh, dismissed the findings as a “lousy job of intelligence.”

The U.N. Security Council has imposed four rounds of sanctions on Iran for failing to suspend sensitive nuclear activities. Russia and China have expressed reluctance against imposing additional U.N. sanctions on Tehran.