An American-born citizen who federal authorities say recently scouted locations in Cleveland to attack people watching Fourth of July fireworks and talked of carrying out additional bombings has been charged with trying to support terrorism.

Federal authorities said Monday that Demetrius Pitts had expressed his support for al-Qaida for more than a year and talked about setting off bombs at a July 4 parade and later in his hometown, Philadelphia.

Pitts, who lived most recently in Maple Heights, Ohio, was due in federal court on Monday in Cleveland. There were no court documents listing an attorney for him, and he couldn't be reached for comment.

Pitts was arrested Sunday after meeting an undercover agent and was charged with attempted support of a terrorist organization.

FBI agent Stephen Anthony said it was unclear how close Pitts was to carrying out his threats, but he said authorities couldn't sit back and wait to find out.

"We don't have the luxury of hoping an individual decides not to harm someone or get others to act," he said.

Anthony said that Pitts, 48, had been radicalized in the U.S. but he had no information that Pitts had traveled out of the country.

Authorities first began watching Pitts in 2017, when he lived in the Cincinnati area, after he made Facebook posts threatening violence against the U.S., Anthony said. Pitts moved to Cleveland in May.

Pitts began meeting with an undercover agent and discussed several ways to carry out an attack, according to court documents. Pitts also talked about his hatred for the U.S. military, Anthony said.

An undercover agent in late June gave Pitts a bus pass and a cellphone that he thought were from al-Qaida supporters so that he could go downtown and look for locations to carry out his attacks, according to a complaint filed by authorities.

Pitts shot videos of potential targets such as a federal building and a U.S. Coast Guard station and then turned over the phone last week, believing the photos and videos would be given to al-Qaida members, the document said.

In recent weeks, Pitts also talked about wanting to travel to Philadelphia, and on Sunday he told the undercover agent he wanted to conduct reconnaissance for an attack using a truck packed with explosives, similar to the 1995 Oklahoma City bombing, authorities said in the complaint.

Pitts told the agent that Philadelphia would be the "big target" and that the attack "will be done" on Labor Day, according to an affidavit. Pitts also pointed to possible targets, including Philadelphia's City Hall and a federal building, the court document said.

In Washington, White House spokeswoman Sarah Huckabee Sanders said that "President Trump commends the work of the DOJ and the FBI in helping stop this would-be attacker."