WASHINGTON (AP) — President Donald Trump has no plans to cut Social Security or Medicare, Treasury Secretary Steven Mnuchin said Sunday. Capitol Hill aides say the White House is moving to propose slashing cuts to longtime Republican targets like the Environmental Protection Agency as it prepares its budget for the upcoming fiscal year.

The White House budget office will send agencies proposed levels for the 2018 budget year on Monday, according to the aides. They spoke on condition of anonymity to discuss nonpublic information and a sensitive process.

The Pentagon is due for a huge boost, but many nondefense agencies and foreign aid programs are facing cuts. The specific numbers aren't final and agencies will have a chance to argue against the cuts.

In an interview with Fox News Channel's "Sunday Morning Futures," Mnuchin said cuts to Social Security and Medicare would not be part of the administration's first budget. Trump's priority is passing legislation to reduce middle-class and corporate taxes, he said.

Asked about potential cuts to the programs on ABC's "This Week," deputy White House press secretary Sarah Huckabee Sanders said Trump is committed to keeping his campaign promise to leave Medicare and Social Security alone.

"I don't see any reason to start thinking differently," she said.

Trump's budget is expected in mid-March.