(CNSNews.com) - Rep. Peter King (R-N.Y.), chairman of the House Subcommittee on Counterterrorism and Intelligence, said what's happening in Europe is a "terrible humanitarian crisis," and while "every effort must be made," he also warned of potential danger if the United States admits Syrians and others who are not thoroughly vetted.
"We had a hearing on this just several months ago in my subcommittee. The clear consensus is that there is a real concern," King told CNN's Wolf Blitzer on Monday. "We have to assume that ISIS or al Qaeda would try to take advantage of this situation."
King said his obligation -- and that of the U.S. government -- is to protect American citizens: "So we have to have a very thorough vetting process. And when people talk about large numbers coming there, I don't see how we could do that, because we have no intelligence on the ground. There's no way of knowing without extensive vetting and investigation who these people are, what their background is.
"I think one way we could do it is take refugees already in Jordan, because Jordan does have very good intelligence and also worked with them and the relief organizations over there. Maybe take some of them to alleviate the pressure on Jordan...All I'm saying is, keep our eyes open."
King said he doesn't want to explain in a year or two "why someone who came in under the guise of being a refugee was responsible for something like the Boston Marathon bombing or subway attack in New York."
Blitzer asked King if he would support "more funding to ease the crisis" that's "exploding" in Europe.
"Yeah. I certainly would," King responded. "The world has an obligation, and the U.S. -- we can go back to the Hungarian freedom fighters, Vietnamese boat people where the U.S. did the right thing. We can go back to the Jews in the 1930s where we didn't do the right thing. So we realize there's an obligation when there is a refugee crisis to step up.
"In the past, we did not have to worry about those refugees being infiltrated by people who carry out attacks in the U.S. I use the example of the Tsarnaev brothers who carried out the Boston Marathon bombing. They were vetted. They had been given in political asylum as refugees and we saw what they did.
"So I'm willing to say that the overwhelming, maybe 90 percent, 95 percent -- who knows what the number -- a very high percentage of refugees are people who deserve and should receive humanitarian aid, but I'm concerned if you get five, 10, 15, 20, whatever the number of terrorists coming in, the damage they could cause, the devastation -- and this week of 9/11 (anniversary), I'm particularly reminded of that."
British Prime Minister David Cameron said his country would resettle up to 20,000 Syrians from camps in Turkey, Jordan and Syria over the next five years.
"The whole country has been deeply moved by the heartbreaking images we have seen over the past few days," he told Parliament. "It is absolutely right that Britain should fulfill its moral responsibility to help those refugees."
French President Francois Hollande said his country would take in 24,000 refugees over the next two years.
Germany, which has an open-door policy toward refugees, has promised to spend billions of euros in extra aid for those already there and those yet to arrive.
According to the Associated Press, more than 340,000 people from the Middle East, Africa and Asia are already seeking refuge in Europe.
(The Associated Press contributed the information on the refugee situation in Europe.)