Last Updated Jul 14, 2016 9:43 PM EDT
Donald Trump weighed in on the deadly Bastille Day massacre in Nice, France, where several dozen people were reported dead after a truck plowed through crowds celebrating the country's independence day.
Asked on Fox News Channel's "On the Record with Greta Van Susteren" for his reaction, Trump responded, "Well, it sounds like here we go again. It's going to be a whole different world. We're living in a whole different world. There is no respect for law and order. There is no respect for anything or anybody. And this has to be dealt with very harshly."
Pressed on what he'd do to prevent any further attacks, Trump asserted that he would make it "very, very hard for people to come into our country" from "terrorist areas."
"I would be so extreme in terms of documentation," the presumptive GOP presidential candidate said. "Obama is allowing a lot of people to come in. We have no idea who they are. They're from Syria, maybe, but they have no paperwork many times. they don't have proper documentation. I would make it -- I would not allow people to come in from terrorist nations. I would do extreme vetting. I would call it 'extreme vetting,' too."
When Van Susteren pointed out that these attacks aren't solely initiated by overseas actors, and that homegrown terrorists are also a problem -- pointing to the massacre in Orlando, Florida last month by a U.S. citizen -- Trump pushed back and said that "second generation" immigrants were also "very bad."
"Second generation turns out to be very bad for whatever reason," the candidate said. "But second generation and again, who knows the new one in France? Maybe it's not, but you probably have a pretty good gut instinct."
In a separate interview with Fox News' Bill O'Reilly, Trump was asked if he would ask Congress for a declaration of war against ISIS. He responded: "I would. I would. This is war."
In a tweet Thursday evening, Trump postponed his vice presidential announcement, scheduled for Friday at 11 a.m., in light of the attack. The campaign has yet to release further details of the press conference.
Following his appearances on the cable shows, Trump also tweeted his condolences for the victims:
Trump's general election rival, presumptive Democratic nominee Hillary Clinton also phoned in for an interview with Fox News' O'Reilly Thursday night to discuss the attack in Nice.
The former secretary of state stressed the importance of America's alliance with France in her interview and urged need for the the U.S. to "stand strongly with them."
"Events like this," she said, "remind us how vital -- vital -- it is in every way not to abandon them. We need to strengthen our alliances, and I include NATO in that. We've got to do more to understand that this is a war against these terrorist groups."
Clinton named a counter-terrorism "intelligence surge" as one of her top priorities as president, pushing for increased cooperation among U.S. agencies and allied countries.
"We need strong, tough diplomacy starting with our friends," she said, "collectively with the EU, with NATO, and with others."
In a separate interview with CNN Thursday evening, Clinton said she was "sick at heart" over the "horrific" attack, which left upwards of 75 people dead.
The former secretary acknowledged that in order to prevail over terror groups, "it's a different kind of war" the U.S. must fight."We need to be smart about how we wage it and win it," she said. "We're at war against radical jihadists who use Islam to recruit and radicalize others in order to pursue their evil agenda. It's not so important what we call these people as to what we do about them." Republicans, including Trump, Ted Cruz, and others, have insisted that radical jihadists be called "radical islamists" and have criticized Clinton and Obama for not adopting the term. Clinton, after the Orlando shooting last month, said that "to me, radical jihadist, radical Islamism, I think they mean the same thing. I'm happy to say either."
She pointed to how the U.S. took out al-Qaeda leader Osama bin Laden as a blueprint for how she would defeat terror groups.
"I think back to our success in getting bin Laden," Clinton said. "It was important that we built the case, we got the information, and that the President ordered the raid."