President Trump proposed deep spending cuts to the State Department and foreign aid in order to appear fiscally responsible while ignoring entitlement spending, a top Senate Republican charged Tuesday.

"This president took an inordinate amount of cuts in this particular area to demonstrate that he was trying to address fiscal issues because, in fairness, [he's] unwilling to address all the other issues that are driving spending so much," Senate Foreign Relations Chairman Bob Corker, R-Tenn., said during a Tuesday hearing at the Senate Foreign Relations Committee.

He spoke just before Secretary of State Rex Tillerson was set to testify there about the State Department budget.

Corker, who was once a contender to lead the State Department or even serve as Trump's running mate, offered his assessment at the outset of a hearing on Trump's proposed State Department budget. Secretary of State Rex Tillerson appeared before the committee to defend a proposal to cut diplomatic spending by about one-third, but Corker declared the idea dead on arrival.

"What comes out of Congress is likely not going to resemble what is being presented today," he said.

Tillerson argued that the diplomatic corps could make do with less money, particularly in light of his plan to reorganize the State Department and United States Agency for International Development.

"I am listening to what my people tell me are the challenges facing them and how we can produce a more efficient and effective State Department and USAID," Tillerson said in his prepared testimony. "Throughout my career, I have never believed, or experienced, that the level of funding devoted to a goal is the most important factor in achieving it. Our budget will never determine our ability to be effective – our people will."

Trump wants to cut diplomatic spending by $10.1 billion, in part to offset an increase in defense spending without going over spending caps set by federal law. The resulting $27.1 billion diplomatic spending budget would be lower than the $34.9 billion that George W. Bush requested in his last budget, but higher than the $23.9 billion Bush wanted in his first budget request.

Tillerson has defended the cuts as a necessary correction of recent spending hikes. "The level of spending that the State Department has been undertaking in the past – and particularly in this past year – is simply not sustainable," he told reporters in March.

However, his team echoed some congressional concerns in an internal memo appealing for changes Trump's initial budget request. "[Tillerson] is deeply concerned about the timing and the size of the reductions and he will appeal to rationalize and reduce our size and structure in a matter that makes us leaner and more efficient," according to a State Department memo to the White House Office and Management and Budget.

Corker admitted that he couldn't bring himself to review Trump's budget request during a staff meeting on Monday. "After about five minutes, I said, this is a total waste of time, I don't want to do this anymore," he said. "And the reason it's a waste of time is, I think you know, the budget that's being presented is not going to be the budget we're going to deal with. It's just not. The fact is that Congress has a tremendous respect for the diplomatic efforts that are underway and the aid that we provide in emergency situations."

The Tennessee Republican acknowledged a looming "fiscal calamity," but suggested that the State Department cuts wouldn't help if Trump doesn't tackle entitlement spending. "Over the last 17 years, our nation has been unwilling to deal with fiscal issues that we face and so 70 percent of the budget is off-budget," Corker told Tillerson. "So until we have a person who runs for president who says they're going to serve one term, they're going to try to deal with these issues, unfortunately, we're heading to a place that to me is a fiscal calamity."