Donald Trump’s top two picks to become the next Veterans Affairs secretary abruptly withdrew their names over the weekend, leaving a shrinking list of candidates for the Cabinet post and a host of uncertainty surrounding the next administration’s ambitious reform plans.

On Saturday, Florida businessman Luis Quinonez announced he would not pursue the job due to health issues. Within hours, Cleveland Clinic CEO Toby Cosgrove also removed himself from consideration, marking the second time in three years the well-known health care executive has turned down such an offer.

Both men had met with the president-elect several times about overseeing the agency, which employs about 365,000 people and has an annual budget nearing $180 billion. Trump announced nominees to lead nearly every other major government department before the end of last year.

The president-elect has described the current department as broken and vowed to massively expand private care options for veterans, root out waste within veterans programs and restore public confidence in a department still reeling from the 2014 wait times scandal.

He also promised to enact many of those changes within his first 100 days in office. Transition teams have been laying the groundwork for those reforms for weeks, but it’s unclear how far that work can progress without a new VA secretary.

It’s also increasingly unlikely that a new secretary will be in place by the end of January, since the Senate confirmation process typically takes several weeks even for non-controversial candidates.

Veterans groups have expressed frustration with the pace of transition, and requested meetings with Trump to voice their desires for the department's future.

Multiple groups have publicly supported the idea of keeping current VA Secretary Bob McDonald in place, but Trump officials have dismissed the idea.

The leading remaining candidates include Fox News host Pete Hegseth, former president of the conservative advocacy group Concerned Veterans for America, and former Massachusetts Sen. Scott Brown. Both have met with Trump multiple times in recent weeks.

Donald Trump has vowed to “rebuild the military” and will get his chance to start as he drafts his first federal budget plan.

Trump's first Pentagon funding request must be complete by April, when temporary legislation funding government operations is set to expire. It will set a baseline for at least the next four years of defense spending.

The president-elect has vowed to grow the Army and Marine Corps, increase Navy shipbuilding and boost the number of Air Force fighter aircraft. He also wants more money to modernize U.S. nuclear weapons systems and more investment in cyber security.

Over President Obama's objections, Congress in December passed legislation that funds the addition of 23,000 troops across the Army, Air Force and Marine Corps. By some estimates, Trump's long-term plans could see the active-duty force grow by almost another 140,000 personnel.

Some observers have called such plans prohibitively expensive. The National Taxpayers Union Foundation, for instance, estimates — at minimum — those plans will require an annual defense spending boost of 3 percent. The Committee for a Responsible Federal Budget has pegged the cost at an additional $150 billion in coming years.

That could be a tough ask, given the focus among conservatives in Congress who have campaigned on reducing government spending.

Trump has said he's confident that savings can be found by cutting bureaucracy and better policing government waste. But few independent analysts believe such reductions will be enough to offset the cost.

For Department of Defense, taxpayers in the United States are paying $528.49 billion, not including the cost of war. Here's what those tax dollars could have paid for instead: