ATLANTA — A Georgia man was arrested Wednesday on suspicion of planning to attack the White House with explosives and other weapons, federal prosecutors said.

Investigators monitored the man for months, and then arrested him when he tried to buy weapons from an undercover FBI employee posing as a dealer, according to an FBI affidavit.

The suspect, identified as Hasher Jallal Taheb, 21, of Cumming, Georgia, had also discussed attacking other buildings in the Washington area, and at one point said he wanted to attack the Statue of Liberty, according to the affidavit. Officials said Wednesday that the suspect was believed to have acted alone.

“All potential threats have been neutralized, and they have been under control from the inception of this case,” Byung J. Pak, the U.S. attorney for the Northern District of Georgia, said at a brief news conference in downtown Atlanta announcing the arrest.

It was not clear whether Taheb had a lawyer to represent him. A call to the Atlanta federal public defender’s office was not returned.

The affidavit supporting the criminal complaint against Taheb says that the FBI was contacted in March by a person who warned that Taheb had “become radicalized, changed his name, and made plans to travel abroad.”

Federal authorities in the court documents did not identify Taheb as a member of any particular terror group. They said he had sent his two presumed collaborators a link to a video by Anwar al-Awlaki, the radical leader of al-Qaida in the Arabian Peninsula, who was killed in Yemen in 2011.

The bureau’s monitoring of Taheb continued after the partial government shutdown began Dec. 22. Thousands of FBI employees have been furloughed during the shutdown, and thousands of special agents have had to work without pay.

In October, the affidavit says, a confidential FBI source met with Taheb, who said he wanted to travel to an area controlled by the Islamic State but had no passport. The affidavit says Taheb told the source that he had decided to attack targets in the United States instead.

Taheb had other meetings with the FBI source and an undercover FBI employee, in which he showed them drawings of White House floor plans and said he would lead them in an attack that he described as “a martyrdom operation,” according to the document.

In December, he asked the undercover employee to obtain weapons for the attack, saying he wanted to use improvised explosive devices, hand grenades, semi-automatic weapons and a shoulder-fired anti-armor weapon, the affidavit says. He said he intended to use the shoulder-fired weapon to blow a hole in the White House, after which the group would “go in and take down as many (people) as they possibly could,” the affidavit states.

The FBI account says that Taheb wanted to record a video featuring clips of “oppressed Muslims,” with American and Israeli flags burning in the background, and that he spoke of also wanting to attack the Washington Monument, the Lincoln Memorial and “a specific synagogue” that the affidavit did not name.

After numerous contacts with the FBI source and the undercover employee, whom he thought would join him in the attack, Taheb went with them to a parking lot in Buford, Georgia, where he thought they would be trading their vehicles for three assault rifles, three explosive devices and the shoulder-fired weapon, according to the affidavit. The FBI brought the weapons he had requested to the scene in a tractor-trailer.

Taheb was arrested after taking possession of them, the affidavit states.

This article originally appeared in The New York Times.