President-elect Donald Trump Donald John TrumpBarr criticizes DOJ in speech declaring all agency power 'is invested in the attorney general' Military leaders asked about using heat ray on protesters outside White House: report Powell warns failure to reach COVID-19 deal could 'scar and damage' economy MORE wants to expand the Navy's fleet to 350 ships, the largest build-up since the end of the Cold War.

But where that money will come from is unclear and defense contractors aren't counting their ships yet.

Experts say that going from the current fleet of 274 ships to Trump's 350 goal will cost about $165 billion over 30 years. And it will be impossible to achieve unless there's a dramatic increase in the defense budget, currently at $619 billion.

Navy budget expert Ronald O'Rourke said the $165 billion price tag does not include broader costs such as staffing the ships, maintenance and operations.

ADVERTISEMENT

"The cost to build the ships is just a fraction of this larger number," O'Rourke, a Congressional Research Service analyst, told The Hill. "It's some much more substantial amount of money that would be needed."

There are expectations on Capitol Hill and within the Pentagon that Trump will substantially increase the defense budget.

Sen. John McCain John Sidney McCainKelly's lead widens to 10 points in Arizona Senate race: poll COVID response shows a way forward on private gun sale checks Trump pulls into must-win Arizona trailing in polls MORE (Ariz.) and Rep. Mac Thornberry (Texas), the chairmen of the Armed Services Committees, are preparing a 2018 defense budget plan of about $640 billion, according to a source close to the House panel. And the Navy added more ships to its 30-year shipbuilding plan after Trump's election.

Trump has ambitious plans for the military.

On the campaign trail, he called for a plan to grow the military that experts say would raise the current Pentagon budget by 20 percent.

Retired Marine Gen. James Mattis, Trump's nominee for Defense Secretary, has also voiced support for increasing the size of the military and number of ships.

However, there are key obstacles to raising defense spending.

The first is the 2011 Budget Control Act, which imposed budget ceilings on defense spending after Congress failed to agree on tax and spending reform. The ceilings are referred to as sequestration, or sequester, and go through 2021.

Overturning the bill would require the new GOP-led Congress to pass a new law, which would be a daunting task, if members can't agree on how to otherwise reduce the deficit.

The only other option for Republican leaders in Congress is comprising with Democrats to lift the defense budget ceilings for several years at a time -- which Congress has done since the ceilings began in 2013.

But Democrats have only been willing to raise the ceilings on defense if non-defense spending is raised as well. Senate Democrats can also still filibuster any GOP plan to raise defense spending, as in previous years.

And there is pressure on Trump from other quarters to keep federal spending low, including the conservative House Freedom Caucus.

Last year, they successfully pushed to extend a short-term government spending measure, known as a continuing resolution, through April 2017, giving the Trump administration to chance to weigh in.

Trump's appointee for the Office of Management and Budget, Rep. Mick Mulvaney (R-S.C.), is also a fiscal hawk hostile to increased defense spending.

If the ceilings can't be overturned or raised, then money for the new shipbuilding plan and associated costs will have to come from elsewhere in the defense budget, at the expense of other programs.

That could spark significant pushback from within the Pentagon.

Trump had said repeatedly on the campaign trail that he would seek to overturn the budget ceilings and raise defense spending.

"We will also repeal the Obama-Clinton defense sequester, and rebuild our badly depleted military," he said at a Nov. 7 rally in Scranton, Pa.

Defense hawks plan to hold Trump to this promise.

"He says he wants to spend a lot more money on defense -- I take him at his word," said McCain.

How Trump will reconcile these competing expectations is anyone's guess, experts say.

"That's the $100 billion dollar question," said Center for Strategic and International Studies director of defense budget analysis Todd Harrison. "You've got an inherent contradiction."

Harrison said Trump will also be using his political capital on a number of other priorities including repealing ObamaCare and tax reform.

"How much will be left over when it comes to the defense budget?" he said. "I don't think we're going to see a dramatic increase in defense spending."

Some in the defense industry are worried that lawmakers will pass another year-long continuing resolution to fund the government. That would mean carrying over spending levels from the previous year, which could lead to the delay of new defense programs.

One industry official urged lawmakers not to wait until current government spending expires at the end of April, worried they would just extend current spending levels through the end of fiscal year in September.

While there is optimism the ceilings on defense spending can be raised, there is also skepticism that Trump can overturn them permanently.

"[Trump] campaigned for the end of sequester," the industry official said, but added that he is seemingly walking back other promises, such as having Mexico pay for a wall along the U.S.-Mexico border.

"The same may be true for sequester," the official said.