House Speaker Paul Ryan said Tuesday that he did not believe a ban on Muslims entering the United States would be in the country's best interest.
Such a ban has been suggested by Donald Trump, the presumptive Republican presidential nominee.
"This is a war with radical Islam, it is not a war with Islam," Ryan said. "Muslims are our partners: The vast, vast majority of Muslims in this country and around the world are moderate, they're peaceful, they're tolerant."
"I do not think a Muslim ban is in our country's interests, I do not think it is reflective of our principles, not just as a party but as a country," he said. "And I think the smarter way to go in all respects is to have a security test, and not a religious test."
Facing a question on whether a ban on Muslims entering the country would even be constitutional, Ryan simply pointed to the Immigration and Nationality Act of 1952 "to determine whether or not the president has that kind of discretion."
In a Monday afternoon address, Trump said the White House has such power.
"The immigration laws of the United States give the president powers to suspend entry into the country of any class of persons. ... I would use this power to protect the American people. When I'm elected, I will suspend immigration from areas of the world where there is a proven history of terrorism against the United States, Europe or our allies, until we fully understand how to end these threats," Trump said, adding that "we have no choice."
Trump called for immigration reform that "serves the interests and values of America."
"We cannot continue to allow thousands upon thousands of people to pour into our country, many of whom have the same thought process as this savage killer," he said, adding that "many of the principles of radical Islam are incompatible with Western values and institutions."
This story is developing. Please check back for further updates.
— CNBC's Christine Wang contributed to this report.