Mnuchin said the administration is sticking by another Trump priority: eliminating the favorable tax treatment for hedge fund managers.
In an interview with CNBC, Mnuchin also said the administration would "absolutely" consider making the tax cuts effective back to the start of this year if a measure didn't pass until 2018.
"I can't speak to the specifics", he said at the CNBC Institutional Investor Delivering Alpha Conference in NY, when asked about the matter.
Mnuchin said he hopes Republicans can get a tax overhaul through Congress by the end of the year.
Trump vowed to reduce the corporate tax to 15 percent to attract more companies to do business in the United States. Instead, Ryan said a number in the low-to-mid 20s is more realistic.More news: Saudi Arabia, UAE, Venezuela open to extending oil production cuts
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The Treasury secretary said the administration still wanted the carried interest break to be available to "other entities that create jobs". But if Republicans want to pass a tax bill through reconciliation to prevent a Democratic filibuster, the legislation can't add to the deficit outside the budget window. The top individual income tax rate is 39.6 percent, though Trump and congressional Republicans have proposed cutting it to 35 percent.
"It was important that the president reached out to Democrats and showed he could get things done on a bipartisan basis", the Treasury secretary said.
Mnuchin also said that he is considering backdating any tax changes to January 1 of this year, which "would be a big boon for the economy".
Mnuchin on Tuesday also said he recognizes that it's important to have good working relationships with both parties, noting that he met with House Speaker Paul Ryan Monday and that Ryan had also had dinner together.