A Virginia man will spend at least 25 years in prison after admitting he tried to conduct a suicide bomb attack against the U.S. Capitol.

Amine El Khalifi, 29, an illegal immigrant from Morocco living in Alexandria, pleaded guilty Friday in U.S. District Court, admitting that he plotted with men he thought were Al Qaeda operatives to attack the Capitol. In reality, El Khalifi was the target of an undercover FBI operation.

He was arrested in February in a parking garage near the Capitol, wearing what he thought was an explosive-laden suicide vest. The vest, provided by undercover operatives, was actually inert. A gun he planned to use to shoot his way past security in the building was also inoperable.

Friday's plea deal requires the judge to sentence El Khalifi to a term of between 25 and 30 years when the sentencing is held Sept. 14. In the plea deal, prosecutors state they will ask for a 30-year sentence.