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The State Department on Tuesday alerted U.S. citizens traveling to Europe to heightened risks of terrorism, and Sen. Jeff Sessions (R-AL) believes that an influx of illegal immigrants from the Middle East is to blame.

Sessions, who is Donald Trump's national security advisor, said that the presumptive Republican nominee believes in properly vetting any refugees who enter the U.S., which is not something that European countries have done.

"They are coming in like we have people coming across the border, with no real ability to evaluate their background or danger," Sessions said.

He asserted that the solution is for the U.S. and European countries to first make it clear that people will not be allowed to enter illegally, and then focus on creating safe zones for refugees near the countries they are fleeing.

"I really believe we can create safe zones in Turkey, in Syria, where people can live safely there, close to their homes, so they can be returned as soon as possible," Sessions said. "It just cannot be the policy of the United States that when there is a war-torn area, everybody is entitled to come here."

He added that Europe cannot continue to accept millions more refugees, because it's destabilizing the continent.

"It's already causing this danger zone. Crime is up dramatically, protests are up all around," Sessions explained. "The right thing to do is to create safe zones there, make them work and try to end the war as soon as possible, so stability can return and people can return."

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