White House Press Secretary Sarah Huckabee Sanders played coy when asked about a tweet President Donald Trump posted Sunday indicating he wants to shift Pentagon funds to his southern border wall project, currently managed by the Department of Homeland Security.

He retweeted the original again Tuesday.

So far, however, Trump’s aides have been unable to provide any evidence  the Pentagon-to-DHS transfer is anything but another headline-grabbing tweet by a president who has never before dealt with the federal budgeting process. Nor have they produced any signs the tweet is being backed by an actual policy process.

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Such an action, called a “reprogramming,” would require approval of the House and Senate Appropriations and Armed Services committees. Any objection from just a single defense panel would sink any formal request in its tracks. But administration officials cannot even say if such an official request is being crafted.

“Build WALL through M!” the commander in chief wrote in a tweet that otherwise was about military funding included in the $1.3 trillion omnibus spending bill he reluctantly signed into law Friday.

Because of the $700 & $716 Billion Dollars gotten to rebuild our Military, many jobs are created and our Military is again rich. Building a great Border Wall, with drugs (poison) and enemy combatants pouring into our Country, is all about National Defense. Build WALL through M!

— Donald J. Trump (@realDonaldTrump) March 25, 2018

A deputy White House spokeswoman did not respond to an inquiry Sunday on what the president seemed to be floating and whether conversations with top appropriators had taken place.

Sanders declined Tuesday to provide any specifics to reporters. But she did say Trump will work with the White House counsel’s office to ensure any actions on border wall funding is legal and within his executive authorities.

Those questions came during her daily press briefing. After she left, several aides were unable to say whether anyone at the White House had contacted Appropriations Committee leaders or senior staffers to measure whether approval for such a high-profile funds shift is even feasible.

Spokespersons for the House and Senate Appropriations committees and the Armed Services panels in both chambers also have not responded to inquiries.

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During the briefing, Sanders declined to say from which Pentagon programs — many already over budget and behind schedule, and likely made more so if monies are diverted — Trump is considering dipping into to help pay for his border barrier.

Asked if there has been any movement to attempt to lawfully implement the idea floated in the president’s Sunday tweet, press aides pointed to the Office of Management and Budget. A spokeswoman for that office has yet to respond.