An 18-year-old Minnesota man accused of supporting ISIS the Islamic State (ISIS) and planning a mass shooting at the Mall of America allegedly told an informant that he selected the shopping center as a target "because it’s owned by Jewish," according to federal charges.

Sheikhdoon Abdullahi Mohamud was arrested after purchasing an AK-47-style rifle, magazines and ammunition from an undercover FBI employee. He is federally charged with one count of knowingly receiving a firearm and ammunition while knowing or having reason to believe they would be used in a felony or federal crime of terrorism.

Court documents detail months of communications over messaging applications and TikTok between Mohamud and an informant. Authorities say that during those exchanges, Mohamud pledged his support for ISIS, discussed his desire to attack the Mall of America and expressed an interest in traveling to Somalia to join a terrorist organization.

According to the charges, Mohamud explained his alleged choice of target in one message, writing that he wanted to attack the mall "because its [sic] owned by Jewish so if I kill even 30 people no one would go there anymore. I want to harm the jew [sic] just like brothers in Australia Bondi Beach harmed the Jews. I'll just go grab assault rifle, bomb too complicated, kill maybe 30-60 people insha Allah and have 260 ammo."

The charges also detail messages in which Mohamud allegedly expressed a desire to kill "kuffar," a term referring to non-Muslim "disbelievers."

"I can’t wait until I kill kuffar man. October 24 is the day insha Allah," Mohamud allegedly told an FBI confidential source in September, according to an affidavit filed in federal court in Minnesota.

When the source later asked why he had selected October 24, Mohamud allegedly pointed to a "Hmong Arts Celebration" taking place at the Mall of America that day, saying the event would have "a lot of people."

Authorities say Mohamud ultimately met with a person he believed was a loyal ISIS member to purchase an AK-47-style rifle. The person was actually working undercover for the FBI.

Mohamud was born in the United States and is an American citizen, authorities said. His parents are from Somalia and later became naturalized US citizens, according to multiple federal law enforcement sources who spoke to Fox News Digital.

The sources said Mohamud's parents arrived in the United States through a New York City airport in 2000, although it remains unclear whether they entered as refugees or on visas. His mother became a naturalized US citizen in 2010 and his father in 2017.

Federal authorities also allege that Mohamud discussed wanting to travel to Somalia to join a terrorist organization.

FBI Director Kash Patel said the suspect "allegedly obtained a weapon he hoped to use in a mass casualty attack in support of ISIS, but this FBI arrested him and put a stop to his plans."

"Once again, this FBI is moving more effectively than we ever have before at stopping terrorists before they can attack Americans - with over 1,100 individuals prevented from conducting attacks, over 4,000 foreign terrorist organization related disruptions and arrests, a 38% increase, and more," Patel said. "We will continue to use every resource we have to detect and prevent acts of terrorism and wipe out their networks all over the country. Thank you to FBI Minneapolis, who did an outstanding job in the investigation and likely saved lives."

President Donald Trump also praised the FBI's handling of the case when speaking to reporters Wednesday.

"I did hear about it. And they did a great job. The FBI did a great job," Trump said.

Mohamud appeared before a federal judge in Minnesota on Wednesday for an eight-minute initial hearing, according to federal court records.

US Magistrate Judge Elizabeth Cowan Wright ordered him temporarily detained. Mohamud is scheduled to return to court on October 19 for a preliminary and detention hearing.