President Trump tweeted Sunday night, “Changes to our thought process on terror must be made,” following the latest attack linked to the Islamic State in France after less than two months of calm.

“At some point countries will have to open their eyes & see what is really going on. This kind of sickness & hatred is not compatible with a loving, peaceful, & successful country!” Trump wrote.

A 20-year-old Frenchman born in Chechnya rampaged through a festive Paris neighborhood Saturday evening slashing passers-by with a knife, investigators said. The man, identified as Khamzat Azimov, killed one person and wounded four others in a festive area near Paris’ old opera house. Police shot him to death as he charged them, witnesses said.

ISIS quickly claimed responsibility for the Saturday night attack via its Amaq news agency, saying Azimov was a “soldier” of the terror group.

In a video before the attacks, as Fox News reported, Azimov apparently called on ISIS supporters living in the West to immigrate to the group’s so-called “caliphate,” or else carry out attacks locally.

“They have closed the doors of immigration in our faces, so let’s strike them in the center of their homes,” the man said in French, adding, “We are on the truth ... despite the alliance of all these unbelievers against us, they will not fulfill their goal.”

Trump often has made the case that Europe ought to respond more to terrorism like the U.S. does.

In early May to the National Rifle Association, Trump claimed that gun-toting Parisians could have thwarted Islamic State attackers at Paris’ Bataclan concert hall.

Trump sparked controversy as some in France took offense at his "trigger-firing" hand gesture imitating the Bataclan attackers. Multiple extremists with explosive belts and assault weapons killed 130 people in the 2015 attacks on the Bataclan, Paris cafes and the national stadium.

Laying out his case for dropping the Iran nuclear deal, Trump contended, "If we do nothing, we know exactly what will happen. In just a short period of time, the world’s leading state sponsor of terror will be on the cusp of acquiring the world’s most dangerous weapons."

Along those lines, Trump is set to host NATO Secretary-General Jens Stoltenberg at the White House Thursday to discuss NATO’s role in the international fight against terrorism.

Last month, French President Emmanuel Macron professed a sunny, best-friends relationship, telling Trump that together the U.S. and France would defeat terrorism, curtail weapons of mass destruction in North Korea and Iran, and act together on behalf of the planet.

Secretary of State Mike Pompeo said the United States would lend a hand in the Paris investigation.

“The French authorities with all the intelligence help the United States can provide will do our best to unpack this in the coming hours,” Pompeo said on “Fox News Sunday.”

In a statement released Sunday evening, White House press secretary Sarah Sanders added: “Acts like this only strengthen the resolve of the global coalition to defeat ISIS and drive it out of existence.”

Fox News' Chris Wallace and The Associated Press contributed to this report.