(CNN) -- Saddam Hussein let the world think he had weapons of mass destruction to intimidate Iran and prevent the country from attacking Iraq, according to an FBI agent who interviewed the dictator after his 2003 capture.

Iraqi leader Saddam Hussein in an unknown location in Iraq after his capture in 2003.

According to a CBS report, Hussein claimed he didn't anticipate that the United States would invade Iraq over WMD, agent George Piro said on "60 Minutes," scheduled for Sunday broadcast.

"For him, it was critical that he was seen as still the strong, defiant Saddam. He thought that (faking having the weapons) would prevent the Iranians from reinvading Iraq," said Piro.

During the nearly seven months Piro talked to Hussein, the agent hinted to the Iraqi that he answered directly to President Bush, CBS said in a posting on its Web site.

"He told me he initially miscalculated ... President Bush's intentions. He thought the United States would retaliate with the same type of attack as we did in 1998 ... a four-day aerial attack," Piro said. "He survived that one and he was willing to accept that type of attack."

"He didn't believe the U.S. would invade?" Correspondent Scott Pelley asked.

"No, not initially," Piro answered.

Once it was clear that an invasion was imminent, Hussein asked his generals to hold off the allied forces for two weeks, Piro said. "And at that point, it would go into what he called the secret war," the agent said, referring to the insurgency.

But Piro said he was not sure that the insurgency was indeed part of Hussein's plan. "Well, he would like to take credit for the insurgency," he said.

Hussein had the ability to restart the weapons program and professed to wanting to do that, Piro said.

"He wanted to pursue all of WMD ... to reconstitute his entire WMD program."

Hussein said he was proud he eluded U.S. authorities who searched for him for nine months after the U.S.-led invasion, Piro said.

"What he wanted to really illustrate is ... how he was able to outsmart us," Piro said. "He told me he changed ... the way he traveled. He got rid of his normal vehicles. He got rid of the protective detail that he traveled with, really just to change his signature."

Hussein was hanged in 2006. E-mail to a friend

All About Saddam Hussein • Iraq