Iranian President Mahmoud Ahmadinejad said on Tuesday that Iran will not stop its nuclear work, despite media speculation that Israel is considering military threats. The Iranian President said in a meeting with students in Tehran: "We advise the United States and its ally [Israel] to stop and be ashamed of [their threats] and be aware that Iran will not take one step back [from its nuclear program]...Anyone acting against Iran will gravely regret a military attack." Ahmadinejad was speaking ahead of the publication Wednesday of a report by the International Atomic Energy Agency [IAEA], which is expected to disclose new details of Iranian efforts to build a computer model of a nuclear warhead. Israeli intelligence agencies played a role in helping the International Atomic Energy Agency (IAEA) gather information that is expected to be released later this week and will accuse Iran of developing a nuclear weapon. In addition to Israel, intelligence agencies from the United States and Europe were also instrumental in helping the IAEA compile the report. Israel is expecting the United States to take the lead in pushing the United Nations and other Western countries to impose tougher, new sanctions on Iran following the publication of the incriminating IAEA report. On Tuesday, Defense Minister Ehud Barak played down speculation that Israel intended to strike Iranian nuclear facilities, saying it had not decided to embark on any military operation. "War is not a picnic." he said, "We want a picnic. We don't want a war...[Israel] has not yet decided to embark on any operation,". Therefore dismissing Israeli media speculation that he and Prime Minister Benjamin Netanyahu had chosen that option. But he said Israel had to prepare for "uncomfortable situations" and ultimately bore responsibility for its own security. "All options to curb Iran's nuclear ambitions", he said, "should remain open".