Senate Majority Leader Mitch McConnell, R-Ky., said a budget that drastically cuts State Department funding cannot pass the Senate and is something he would personally oppose.

Asked Tuesday whether a budget that slashed State's funding by a third, as some media reports say President Trump wants to do, McConnell said such a plan would "probably not" pass muster in Congress.

"When we get to funding the government, obviously, it will be done on a bipartisan basis, and will be an opportunity for our Democratic friends to participate," McConnell said alluding to the need for the support of at least eight Democrats to pass spending bills.

Trump's budget blueprint, which carries no enforcement mechanisms, could, in theory, pass both houses of Congress with simple majorities. But when it comes to actually appropriating the funds, Democrats could put the brakes on bills that slash State Department and domestic funding.

McConnell's personal opposition, however, also signals that Trump's budget could have problems attracting enough Republican backing.

"I, for one, just speaking for myself, think the diplomatic portion of the federal budget" is a positive tool for U.S. foreign policy, McConnell told reporters. He said spending money on diplomacy is often cheaper and more effective than what "we do on the defense side."

But McConnell indicated that he and the Trump administration could work out their differences.

"We'll sort all that out in the course of deciding how much we're going to spend and how we're going to spend it," he said.

McConnell also responded to reports that Trump, in his first major address to Congress, will encourage lawmakers to pass a compromise immigration bill.

The GOP leader said he hasn't talked about it with Trump but noted, "we're all interested in what the president has to say about immigration."