Shamsud-Din Jabbar, 42, a US citizen from Texas, said in videos he had posted on social media that he wanted to kill the American president, Joe Biden.
The attack is the deadliest IS-inspired assault on US soil in years and the latest example of a vehicle being used as a weapon to carry out mass violence.
Mr Biden has condemned the attack in an address to reporters at Camp David but, going into 2025, it reaffirms the threat of the terror group.
Joe Biden makes a statement about the terrorist attack in New Orleans
Chris Kleponis / AFP via Getty Images
Its fighters repeatedly defeated both countries’ armies and carried out or inspired attacks in dozens of cities around the world.
Its then leader, Abu Bakr al-Baghdadi, killed in 2019 by US special forces in north-western Syria, rose from obscurity to lead the ultra-hardline group and declare himself “caliph” of all Muslims.
The caliphate collapsed in Iraq, where it once had a base only a 30-minute drive from Baghdad, and in Syria after a sustained military campaign by a US-led coalition.
The new leader, known by the pseudonym Abu Hafs al-Hashimi al-Quraishi, remains shrouded in secrecy.
But the group’s influence appears to be growing once more.
A black flag with white lettering lies on the ground rolled up behind a pickup truck that a man drove into a crowd on Bourbon Street in New Orleans, killing and injuring a number of people
Gerald Herbert / AP
Was Islamic State behind the attack in New Orleans? Is Isis back?
It has not been said if Jabbar was acting as a fully fledged member of Isis but it does suggest the group that once terrorised parts of the Middle East is making a comeback.
On Wednesday, Isis claimed responsibility for an attack on a military base in Somalia’s north-eastern region of Puntland a day earlier, the group posted on its Telegram channel.
Though largely crushed by a US-led coalition several years ago, IS has managed some major attacks while seeking to rebuild.
They include an assault on a Russian concert hall in March 2024, killing at least 143 people, and two explosions that killed nearly 100 people in the Iranian city of Kerman in January.
It also claimed responsibility for an assault by suicide attackers on a mosque in Oman last year, killing at least nine people.
US Secretary of State Antony Blinken has warned that Islamic State will try to re-establish capabilities in Syria after the ousting of President Bashar al-Assad but said that the United States is determined not to let that happen.
Aside from its bloody operations in the Middle East, Islamic State has also inspired lone-wolf attacks in the West