In an interview with Bloomberg on Tuesday, Republican Senate leader Mitch McConnell said of tax reform that “It will have to be revenue-neutral.” He added, “we have a $21 trillion debt.”

McConnell also suggested there was steep Senate opposition to the House proposal for a border-adjusted tax, which might offset some of a tax cut’s lost revenue.

“You got, for example, two senators from Arkansas,” McConnell noted in reference to Senators John Boozman and Tom Cotton who represent the state where Wal-Mart is headquartered. “Need I say more? It’s a statement of the obvious that the prospects of that would be rather bleak.”

In the meantime, McConnell, along with the House Speaker Paul Ryan, are having regular meetings with Treasury Secretary Steven Mnuchin, and White House economic advisor Gary Cohn to try to reach a consensus before proceeding.