WASHINGTON — President Donald Trump’s chief economic adviser said Thursday he “can’t guarantee” that some middle-class families wouldn’t see increases to their tax bills under the GOP leadership’s plan for sweeping changes to the system.

White House National Economic Council director Gary Cohn also wouldn’t say whether the administration is willing to abandon a proposal to scrap deductions for state and local taxes.

“The one thing I would beg you all to do is don’t look at any one piece. Look at the plan in its entirety, ” he told reporters, adding, “We’re committed to it, and we’re sticking with it.”

His remarks came after Trump promoted the blueprint Wednesday as a “middle-class miracle,” unveiling what he, Senate Majority Leader Mitch McConnell (R-Ky.) and House Speaker Paul Ryan (R-Wis.) called a “once-in-a-generation” opportunity to usher in tax relief and simplify the tax code.

Democrats forcefully denounced the framework as helping the nation’s wealthiest at a cost to everyday Americans, citing such proposals as the elimination of state and local tax deductions.

Trump “said his tax plan would create a middle-class miracle. I think it would be a miracle if it helped the middle class,” Senate Minority Leader Chuck Schumer (D-N.Y.) tweeted Thursday.

advertisement | advertise on newsday

Cohn told ABC’s “Good Morning America” that though the plan is “aimed” at alleviating the tax burden for middle-class families, he wouldn’t make promises.

“There’s an exception to every rule,” he said. “I can’t guarantee anything. You can always find a unique family somewhere.”

Later at the White House, he echoed, “I cannot guarantee that. You could find me someone in the country that their taxes may not go down.”

The former investment banker also did not say yes when asked if the administration would be willing to back away — during negotiations with Congress — from the proposed elimination of state and local tax deductions. “Seventy-five percent of American families do not itemize,” he noted.

Currently, New Yorkers and others in highly taxed states have the ability to deduct what they pay in state and local taxes from their incomes before paying their federal taxes.

Rep. Peter King (R-Seaford) said, “Any tax reform legislation must retain the state and local tax deductions. Hardworking New Yorkers must not be taxed twice.”

Separately, in a “Fox and Friends” interview that aired Thursday morning, Trump said he believes NFL team owners “are afraid of their players.”

The president has been vocal in his criticism of players who decline to stand for the national anthem as disrespectful to the country and military. The protesters, who are mostly black, take a knee instead to protest social injustice and police brutality.

Asked about the “afraid” comment, Press Secretary Sarah Huckabee Sanders said the president was referencing “probably the backlash of the players and . . . not wanting to create that conflict within their team.”