Gary Cohn, the chief economic adviser to President Donald Trump, said the tax reform package has to get done this year, The Wall Street Journal reports.
"Look, I think it's really important to get it done," he said. "We've got to get taxes done this year. The legislative calendar is going to get very crowded come the first and second week of December."
Trump has expressed hope he can sign a bill by Christmas.
Cohn's comments came during the Wall Street Journal's CEO Council on Tuesday.
Cohn defended the House and Senate tax bills and said they both lessen tax burdens for middle-class families. He said he was not concerned about lawmakers hesitancy to back any plan with provisions that would reduce or eliminate federal deductions for state and local taxes.
"The only way to grade whether it's successful or not is to literally look at the tables, look at the distributions and say, does this do what we want it do and does it deliver tax relief to hardworking American families?" he said. "And the answer to both bills is, yes it does."
CNN reported the House is expected to vote this week on a tax reform bill.