Trump also lent credence on Wednesday morning to an unconfirmed theory initially floated on extreme-right outlet Breitbart News that Saipov had entered the United States through the Diversity Visa Lottery Program, and laid blame on New York Democrat Senator Chuck Schumer for helping to create the program. The travel dictat was criticised by many and was deemed a "Muslim ban".
"My thoughts, condolences and prayers to the victims and families of the New York City terrorist attack", Trump added. Trump had tweeted after the London terror attack in June. In the 16 years following September 11, he said most domestic attacks committed by foreigners were committed by people who entered the country legally and had no red flags on their record.
Vetting procedures attempt to detect foreign nations who may commit or support acts of terrorism, or pose a threat to national security.
Trump, whom the White House previously said was being briefed on the situation by chief of staff John Kelly, wrote: "In NYC, looks like another attack by a very sick and deranged person".
However, following an attack in Las Vegas in October, in which 58 people were shot dead by Stephen Paddock, an American not associated with Islam, Trump took more than five hours to respond, and did so in a more subdued tone.
At a press briefing, New York City mayor Bill de Blasio and New York governor Andrew Cuomo condemned the attack as an act of terrorism but urged New Yorkers not to be afraid of further attacks.
The brothers who set off two bombs at the Boston Marathon in 2013 came from Kyrgzystan and were children when their family entered the U.S. And Omar Mateen, who killed 49 people in the Pulse nightclub in Orlando in 2016, was born in NY to Afghan parents. He speaks out against "chain migration", and the visa program that allowed the driver into the USA and calls the United States system of justice a "joke". Trump demands "punishment that's far quicker and far greater than the punishment these animals are getting right now".
His clear policy agenda is to change the U.S. immigration system: "I am, today, starting the process of terminating the diversity lottery program", Trump said.