Treasury Secretary nominee Steven Mnuchin believes that banks should be regulated based on the "complexity and activity," rather than just their size, the Wall Street Journal reported.

The nominee shared his thoughts while answering a question about the $50 billion asset threshold pertaining to the 2010 Dodd-Frank financial overhaul law.

After his confirmation hearing last week, the nominee also addressed other regulatory issues in written answers submitted to the Senate Finance Committee members. The written answers were in line with Mnuchin's comments during the hearing. Mnuchin also supports a "comprehensive review" of the institutional processes of the U.S. Financial Stability Oversight Council.

Mnuchin said the Trump administration will also look into the Glass-Steagall law.

"A bright line between commercial and investment banking, although less complicated, may inhibit the necessary lending and capital markets activities to support a robust economy," said Mnuchin. "This is why we have suggested a 21st Century Glass-Steagall may be appropriate," he added, according to the news outlet.

Mnuchin did not give a clear answer on tax cuts. However, while answering a question on tax code section governing like-kind exchanges, he said, "I pledge to examine Section 1031 and give it the attention it merits."

The nominee also avoided clear comment on the border-adjustment proposal in the House Republican tax plan.