Washington (CNN) As President Donald Trump prepares to name a new leader for the sprawling department of Veterans Affairs, officials at the department have been raising the alarm, saying that they'll run out of money for the Veterans Choice Program in the coming weeks.

The Choice program was a campaign priority of the President's and allows patients to seek medical services from private providers at the taxpayer's expense, but Congress has been at an impasse over a long-term fix amid disagreements over the program's cost and how much access the nation's veterans should have to private doctors.

Trump tweeted about the funding shortfall on Thursday, urging lawmakers to act to add funding swiftly.

"This spring marks 4yrs since the Phoenix VA crisis. We won't forget what happened to our GREAT VETS," Trump tweeted. "Choice is vital, but the program needs work & is running out of $. Congress must fix Choice Program by Memorial Day so VETS can get the care they deserve. I will sign immediately!"

The legislation was not included in the federal budget bill that passed in March, after Democrats argued that the legislation was a step toward breaking up VA's health care system.

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