(The Hill) -- President-elect Donald Trump blamed the situation at the U.S.-southern border for the recent attacks in New Orleans and Las Vegas, railing against President Joe Biden for his immigration policies as both cases are being investigated. The man who plowed a pickup truck into a crowd in New Orleans, killing at least 15 people, has been identified as Shamsud-Din Jabbar — a U.S. citizen from Texas. The Cybertruck explosion outside of the Trump International Hotel in Las Vegas was caused by firework mortars and camp fuel canisters and the suspect was reportedly an Army veteran from Colorado, according to local news reports. Still, Trump railed on Truth Social that the border under Biden has led to violent crime. “With the Biden ‘Open Border’s Policy’ I said, many times during Rallies, and elsewhere, that Radical Islamic Terrorism, and other forms of violent crime, will become so bad in America that it will become hard to even imagine or believe,” the president-elect wrote. “That time has come, only worse than ever imagined. Joe Biden is the WORST PRESIDENT IN THE HISTORY OF AMERICA, A COMPLETE AND TOTAL DISASTER," he added. "What he and his group of Election Interfering ‘thugs’ have done to our Country will not soon be forgotten! MAGA." NYPD presence increased at Trump Tower, Times Square after attacks in New Orleans, Las Vegas The suspect in New Orleans was carrying an Islamic State (ISIS) extremist group flag on the trailer hitch of the truck he rented for the attack. The FBI said it was working to determine Jabbar’s potential associations and affiliations with terrorist organizations. Around midnight on Thursday, Trump also said the “USA is breaking down” after the attacks. "Our Country is a disaster, a laughing stock all over the World! This is what happens when you have OPEN BORDERS, with weak, ineffective, and virtually nonexistent leadership. The DOJ, FBI, and Democrat state and local prosecutors have not done their job," he wrote. "They are incompetent and corrupt, having spent all of their waking hours unlawfully attacking their political opponent, ME, rather than focusing on protecting Americans from the outside and inside violent SCUM that has infiltrated all aspects of our government, and our Nation itself,” the president-elect continued. “Democrats should be ashamed of themselves for allowing this to happen to our Country. The CIA must get involved, NOW, before it is too late," Trump added. "The USA is breaking down — A violent erosion of Safety, National Security, and Democracy is taking place all across our Nation.” He ended his late-night message with, “See you on January 20th,” which is the day he will be sworn in. The president-elect, just hours after the attack, posted a similar message centered on immigration that he shared while on the campaign trail, though he did not explicitly weigh in on Jabbar's citizenship status. Others, however, have jumped to the conclusion that the attacker was not a citizen. Biden in remarks delivered Wednesday, said Jabbar posted videos on social media hours before the attack that “indicated that he was inspired by ISIS” and had a “desire to kill.”