James Clapper, who served as director of national intelligence under President Barack Obama, made his first public comments since leaving office during an exclusive interview with CNN's Jim Sciutto.
"I do worry (the) countries in question with whom we do deal and who are reliable partners, and I also worry about this creating a recruiting tool for the extremists," Clapper said, "that they will point to this proof that there is a war on all Muslims and they are very astute, particularly ISIL, at exploiting for recruitment purposes."
Trump issued an executive order last month that temporarily banned people from Syria, Iraq, Iran, Somalia, Sudan, Yemen and Libya from entering the country until more stringent safeguards and vetting standards for entry could be implemented.
Clapper said while the vetting being done on people entering the country was not "perfect," those actions were strong enough to keep the country safe without this new measure.
Clapper, while noting that he's farther removed from the job each day that goes by, said "I don't believe we, in (the intelligence community), were aware of any extraordinary threats that we weren't already dealing with."
He added, "We were using some very rigorous vetting processes to check people, validate the people were who they claim to be."
In his first public comments on the matter, Clapper said the decision to brief both Trump, who was still the President-elect at the time, and Obama on a dossier alleging Russia had compromising information on Trump was partly due to various media outlets and offices on Capitol Hill having the document.
"We thought it was important that he know about it," Clapper said of Trump. "That was the main point. Not to comment on the veracity" of the information.
In the days following the revelation of the document, first reported by CNN, Trump publicly criticized the intelligence community. He went so far as to compare it to Nazi Germany -- which eventually prompted a phone call from Clapper to Trump.
Clapper said he was "concerned" about the comparison and said the comments made many in the intelligence community "quite upset."
"I felt obliged to call the President-elect and appeal to his higher instincts, and to make sure he understood what our ... motives were." He said that the intelligence community's aim is to "support to the commander in chief, and to keep him as informed as possible, particularly if it involved some jeopardy to him."
Clapper said Trump was "very affable and solicitous" in the call and characterized the discussion as a "success," noting that it was a "constructive engagement."
When Trump visited the CIA the day after his inauguration, Clapper was concerned once again.
"For a couple minutes, it was fine. I actually, I was encouraged when I heard that his first visit after the election was going to be the CIA," the former director said. But then his comments devolved into politics.
Clapper emphasized the importance of the wall for fallen intelligence members that the President stood in front of as "hallowed space, not only for CIA people, but actually for the entire intelligence community."
He added, "I would hope that when people stand in front of edifices like that, that they remember that."
In the wake of the intelligence community's assessment that Russia was behind cyber efforts intended to affect the outcome of the US presidential election, Clapper said Russia still posed a clear threat to the United States.
"I'm sure they've continued" with the hacking, even after intelligence agencies released a report detailing their alleged breaches, he assessed. "I think it's in their DNA, whether during the Soviet Era or now."
And what about possible Russian attempts to interfere in the 2018 midterm or 2020 presidential election?
"I certainly wouldn't put it past them. If they thought it would be to their advantage to influence a national election or a congressional election, they would," Clapper said.
Clapper, a retired Air Force intelligence officer who served under every president since John F. Kennedy, said there were a range of emotions he experienced when he left office last month.
"I think the overriding feeling I had at 12:01 a.m. on the 20th of January was a sense of relief," he said.
While he is "quite anxious" for Sen. Dan Coats to be confirmed to succeed him, Clapper said there is still a sense of apprehension that hangs over him.
"Well, I worry," he said. "I have a lot personally invested in the US intelligence community. It's been a 50-year passion of mine ... so I have a lot invested in it, and yes, I do worry about it."