Congress should pay for the cost of President Donald Trump’s border wall with Mexico, House conservatives said Tuesday, presenting an issue for GOP leaders who have signaled they may not offset a supplemental appropriations measure to fund the wall.

“We will need to find funding for that wall and that will have to come from offsets,” House Freedom Caucus founding member Raul Labrador said during a Tuesday press event with conservative members of the House.

“I believe everything that we do in government, that there should be a pay for,” the Idaho Republican added.

South Carolina Republican Mark Sanford, also a Freedom Caucus member, said he “absolutely concur[s]” that there should be offsets.

At last week’s GOP retreat, Senate Majority Leader Mitch McConnell, R-Ky., and Speaker Paul D. Ryan, R-Wis., pegged the cost of the wall as high as $15 billion, although independent estimates hover as high as $25 billion. The two leaders said then that the president will submit a supplemental appropriations request to Congress asking for funding for the wall early this year after Rep. Mick Mulvaney, R-S.C., is confirmed as the director of the Office of Management and Budget.

Hunt for Billions for Border Wall is On

Ryan and McConnell were noncommittal on whether the supplemental would include offsets. On Friday, Ryan signaled that it may not be paid for with new taxes or spending cuts elsewhere, saying during an event hosted by Politico Playbook that border security is an important matter of natural security.

Ohio Republican Jim Jordan, former chairman of the Freedom Caucus, said that there are several big issues Congress has to deal with this year that involve spending, citing the 2010 health care law repeal and replacement, the border supplemental, a possible plan to do away with the across-the-board budget cuts known as the sequester, the debt ceiling and an infrastructure package as examples.

“We have to be real sensitive that as we go through all these big issues that we’re focused on offsets,” he said.

Current Freedom Caucus Chairman Mark Meadows said he too would like the border wall to be paid for but that he’s not ready to commit to a hardline position on the matter.

“Fiscally responsible legislation would have it as an offset,” the North Carolina Republican said. “That being said, I think it’s so critically important that we get it done that drawing a line in the sand today is not necessarily something that I’m willing to do on how it’s to be offset.”

With Mulvaney, a Freedom Caucus founding member, as OMB director, Congress would have “a willing partner in terms of suggesting possible offsets that the administration could live with,” Meadows added.