By COLLIN BINKLEY AP Education Writer

President Donald Trump will sign an executive order on Thursday requiring U.S. colleges to certify that they protect free speech on their campuses or risk losing federal research funding, White House officials said.

Trump initially proposed the idea during a March 2 speech to conservative activists, highlighting the case of Hayden Williams, an activist who was punched in the face while recruiting for the group Turning Point USA at the University of California, Berkeley. At the time, Trump said that Williams "took a hard punch in the face for all of us."

Under the order, colleges that receive research grants from federal agencies would be required to agree to uphold free speech policies. The order also would apply to certain education grants but not to federal financial aid that covers tuition and fees for students.

For public universities, officials would have to agree that they follow the First Amendment, which already applies to them. Private universities, which have more flexibility in limiting speech, would be required to commit to their own institutional policies.

How the federal government would enforce the order has yet to be seen. White House officials said implementation details will be finalized in the coming months, noting that enforcement will be carried out by the Office of Management and Budget and individual research agencies.

Colleges pursuing grants from research agencies including the National Institutes of Health already are required to certify that they meet certain conditions. The order would simply add free speech protection as one of those conditions, and some colleges have said it's not needed.

Trump's son Donald Trump Jr. on Twitter called it a "momentous day," saying the order will "protect free speech rights for ALL students." He gave credit to Turning Point USA and its founder, Charlie Kirk, adding that Kirk has "been pushing this since the first time I met him years ago."

Kirk has been among a growing chorus of conservatives who say their voices are stifled on college campuses. The debate has flared following a string of high-profile cases in which speakers have been shut down or heckled, including at UC Berkeley and at Middlebury College in Vermont. Often, protests have targeted conservative speakers.

Others who have called for action include Education Secretary Betsy DeVos and former Attorney General Jeff Sessions.

But many colleges say they already have strong free speech policies and don't need an executive order. After Trump's earlier proposal, the University of California issued a statement calling the order "misguided and unnecessary."

It's unclear what type of free speech limitation could trigger a loss of federal research funding. White House officials declined to provide specific cases of free speech suppression.

In the Feb. 19 case at Berkeley that Trump previously cited, neither Williams nor the man arrested for the attack was affiliated with the university.

Some experts have noted that the order could unintentionally force religious universities to host speakers who have views that conflict with the universities' values. Still, the order has gained support from some institutions including Liberty University, a Christian school in Virginia.

Unrelated to free speech, the executive order also tells the Education Department to expand its College Scorecard website to provide students with outcomes data for individual programs within schools. By January 2020, the department will be ordered to publish data including graduates' median earnings, loan debt and default rates, along with similar data for the college overall.

Trump, a Republican, also is asking the Education Department to prepare a policy that would make sure colleges "share the financial risk" that students and the federal government take on with federal student loans.