WASHINGTON, Jan 29 (Reuters) - U.S. Senate Majority Leader Mitch McConnell, a Republican, said the United States needs to "be careful" while implementing President Donald Trump's new executive order targeting immigration from seven predominantly Muslim countries.

McConnell said on ABC's "This Week" program it was a good idea to tighten the vetting of immigrants, but "I also think it's important to remember that some of our best sources in the war against radical Islamic terrorism, are Muslims, both in this country and overseas ... We need to be careful as we do this."

(Reporting by Susan Cornwell; Editing by Jeffrey Benkoe)