MIAMI (Reuters) - Acting U.S. Defense Secretary Patrick Shanahan said on Wednesday he would push ahead with plans to transfer $1 billion to help fund President Donald Trump’s wall on the U.S. border with Mexico, even as he acknowledged a likely backlash from Congress.

New bollard-style U.S.-Mexico border fencing is seen in Santa Teresa, New Mexico, U.S., March 5, 2019. REUTERS/Lucy Nicholson

Democratic Representative Adam Smith, chairman of the House Armed Services Committee, said on Tuesday that the panel did not approve the proposed shift in Pentagon expenditure. Any decision to go ahead anyway could prompt Congress to create new restrictions that could impact the Pentagon in the future.

Asked whether his plan was to move ahead regardless, Shanahan said: “Yes, it is.”

“There are going to be consequences. I understand the position of the committees. I also have a standing legal order from the commander-in-chief,” he said.

Congress could attempt to cut off the Pentagon’s authority to reprogram funds, something Smith hinted at during the hearing.

Asked whether he expected Smith to follow through, Shanahan said: “I would expect that to happen.”

Still, the Pentagon insists it has the authority to shift the $1 billion.

The House failed on Tuesday to override Trump’s first veto of the “national emergency” he declared last month to build a U.S.-Mexico border wall that Congress has not funded.

Smith told the hearing that Trump’s proposed $750 billion defense budget would not pass as it was proposed. That budget included $100 billion in a “slush fund” meant to fund ongoing wars but which the Pentagon intends to use to boost the amount of money it has available to avoid budget caps.

Shanahan said losing the ability to reprogram funds could present problems for Pentagon planners, who have to shift resources around to deal with natural disasters and other emergencies.

“It’s a very difficult situation and ... we’re going to have to be artful to manage this,” he said. “I don’t think it’s going to be easy.