"The minor was inspired by [ISIL] and sought to conduct a detailed homeland attack which included multiple attackers, firearms, and multiple explosives, targeting a foreign dignitary at a high-profile event," ABC News quoted an FBI and Department of Homeland Security (DHS) internal bulletin as saying on August 14.
Sources told ABC News that the "foreign dignitary" mentioned in the bulletin was Pope Francis.
The FBI-DHS bulletin added the 15-year-old had allegedly "obtained explosives instructions and further disseminated these instructions through social media."
In recent weeks, US media as well as Congressman Mike McCaul have reported on the increased security measures the country has taken to thwart potential attacks against the pope during his September visit, as well as attacks that US authorities have prevented.
Pope Francis is scheduled to visit the United States on September 22-27, marking his first papal visit to the country.