On the eve of President Trump's decision on the certification of the Iran nuclear deal, CIA Director Michael Pompeo lashed out Thursday at the Islamic Republic in a speech at the University of Texas, calling it "a thuggish police state" and a "despotic theocracy," and comparing its ambitions to those of ISIS.

The hardline speech, delivered as the keynote at a national security forum in Austin sponsored by the university, is "setting the stage" for the Trump administration's announcement on the nuclear agreement, expected Friday afternoon, said one senior U.S. intelligence official.

Iranian Revolutionary Guards march during a parade commemorating the 31st anniversary of Iran-Iraq war on September 22, 2011 in Tehran, Iran. Kaveh Kazemi / Getty Images file

The president is expected to withhold recertification of the agreement, kicking the issue to Congress, which will have 60 days to reimpose the sanctions lifted after the nuclear deal was made. There are also reports the Trump administration may designate Iran's Revolutionary Guard as a terrorist group. Iran has promised serious "consequences" if the IRGC, an elite military force that answers to the nation's religious leadership, is named a terrorist group. In the past, the U.S. has listed IRGC officers and affiliates as terrorists but has declined to name the group as a whole.

Related: White House Briefs Congress on Iran Decertification Plan

Pompeo's remarks gave no indication of whether the IRGC, officially the Islamic Revolutionary Guard Corps, will be listed as a terrorist organization, but his remarks were, as the U.S. official said, "an aggressive indictment," using unusually harsh language in describing its operations and Iran in general.

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"Iran's Ministry of Intelligence and Security and the Islamic Revolutionary Guard Corps are the cudgels of a despotic theocracy, with the IRGC accountable only to a Supreme Leader," Pompeo said. "They're the vanguard of a pernicious empire that is expanding its power and influence across the Middle East."

He also suggested that the IRGC is becoming bolder in its operations.

"In recent years, the IRGC has become more reckless and provocative, seeking to exploit the vacuum left by instability in the Middle East to aggressively expand its influence," he added. "It openly vows to annihilate Israel. And when you look at the death and destruction inflicted in Syria, Yemen, and Iraq by Tehran and its proxies, the threat is clear: Iran is mounting a ruthless drive to be the hegemonic power in the region."

Related: Trump's Expected Iran Move Would Defy Allies Abroad and at Home

In one passage bound to anger Iran, Pompeo compared Iran to the Sunni terror group ISIS, which Iranian-linked Shiite militias have fought in bloody battles for years.

"For unlike ISIS and its mirage of a caliphate, Iran is a powerful nation-state that remains the world's largest state-sponsor of terrorism. The Islamic Republic is Iran's version of what the caliphate ought to look like under the control of an Ayatollah and his praetorian guard, the IRGC," he said.

CIA Director Mike Pompeo answers questions at the Center for Strategic and International Studies (CSIS) in Washington on April 13. Pablo Martinez Monsivais / AP file

The CIA director also contended that the IRGC had attempted to carry out a terrorist attack in Washington, and suggested a U.S. serviceman had been killed by an IED linked to Iran.

Four years ago, Manssor Arbabsiar was sentenced to 25 years in prison for plotting to assassinate the Saudi Ambassador in Washington. Pompeo said in his speech that Arbabsiar had plotted the attack with the Guards' Quds Force.

While Arbabsiar was convicted, a number of Iranian experts inside and outside the U.S. government questioned whether he was really acting on behalf of the IRGC, suggesting instead that the plot was a "rogue operation."

As for Iran's complicity in attacks using IEDs, or improvised explosive devices, Pompeo mentioned the possibility that a Tyler, Texas, soldier had been killed this month by Iranian weapon, noting he had been killed "in an area controlled by a Shia militia aligned with Iran."

"We do not have evidence of a direct link to Iran," said Pompeo, "but we are closely examining this tragic incident."