A major tax cut promised by US President Donald Trump was on track for final passage next week, after two previous holdouts in his Republican party said Friday they would vote yes on the legislation.

Republicans in both houses of the US Congress, where they hold majorities, each adopted their own versions of the controversial tax code overhaul, and the final compromise text was released late Friday.

"By lowering tax rates, simplifying the rigged and burdensome tax code, and repealing the failed tax on lower- and middle-income households known as the Obamacare individual mandate, this legislation will grow our economy, raise wages and promote economic competitiveness," White House spokeswoman Sarah Sanders said.

Trump "looks forward to fulfilling the promise he made to the American people to give them a tax cut by the end of the year," she added in a statement.