(Bloomberg) — The tax code became too expensive and burdensome under former President Barack Obama's administration, making a review of 2016 and 2017 tax rules necessary, Treasury Secretary Steven Mnuchin said.

And although President Donald Trump's administration is already pushing for a comprehensive overhaul of the U.S. tax code in legislation, it's important to review Obama-era regulations as well, Mnuchin said Friday at the White House, where he detailed the provisions in an executive order President Donald Trump will sign later in the afternoon.

"This has to do with the complexity of tax regulations — some of those issues may be addressed in tax reform, some of those things have nothing to do with tax reform and the president wants to make clear to the American people that we are going to fix the tax code," Mnuchin said.