He published a follow-up stating that the USA "must not allow ISIS to return" and that he was planning to "step up our already Extreme Vetting Program".
But when eight people were mowed down in a terrorist attack by a man shouting "Allahu akbar," President Donald Trump pounced nearly immediately, seizing on the tragedy to push his proposals for tightening immigration controls.
The latest version of the ban, which would bar most people from eight countries from entering the USA, was blocked by two federal judges.
Earlier, the United States president took to Twitter to decry the attack, saying "we must not allow ISIS to return".
Trump also linked the attack to the Islamic State, even though authorities have yet to determine that the suspect has any ties to the terrorist group.
"Extreme vetting is, we simply interview people and have to satisfy ourselves that the person we're talking to is indeed the person who they claim,"he said".
Trump's comments, made during a White House Cabinet meeting Wednesday, malign the justice system for a lack of toughness.More news: Are black passengers treated unfairly on American Airline flights? NAACP says yes
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"We want a merit-based program, where people come into the country based on merit", Trump said.
Trump tweeted after declaring earlier that the attack was perpetrated by "a very sick and deranged person".
However, de Blasco said: "The bottom line is we are going to go about our business. This attack did not take seven years or more to plan", Nowrasteh said.
"Today is a day for consoling the survivors, and mourning those we lost", press secretary Sarah Sanders said on behalf of the White House later that day.
First political blame from Trump: Follows up with tweets the morning of November 1, blaming Democratic New York Sen.
He tweeted: "The terrorist came into our country through what is called the "Diversity Visa Lottery Program", a Chuck Schumer beauty". Trump demands "punishment that's far quicker and far greater than the punishment these animals are getting right now".
Trump has previously talked about his extreme vetting process following a major terrorist attack.