President Donald Trump has declared a national emergency on Friday to fund his promised wall on the US-Mexico border without Congress approval.
An American defense official said on condition of anonymity that Shanahan would likely approve the $ 3.6 billion diverted from the military construction budget.
By declaring a national emergency, Trump may use certain funds from the Ministry of Defense to build the Wall.
By law, the Secretary of Defense must decide whether the wall is militarily necessary before money can be used from the military building budget.
"We always expected that this would attract a lot of attention. Since money could potentially be diverted, you can imagine the concern it causes, "Shanahan told reporters traveling with him from his trip to Afghanistan, the Middle East, and Europe.
"We made very conscious decisions, we identified the steps we would take to make those decisions," Shanahan said.
He added that military planners had carried out the initial analysis and he would start checking them on Sunday.
Officials said the government had found nearly $ 7 billion to bring them back on the wall, including about $ 3.6 billion in military construction budget and $ 2.5 billion from a Defense Department drug ban fund.
The US Defense official said Shanahan would meet with the secretaries of the service in the coming days to find out which projects were going to make the money.
Shanahan said planners had identified the various sources of money that could be used, but he had not decided exactly which projects would be affected, and ultimately, that was his decision.
"I do not have to do anything," he said.
Shanahan said he did not expect to take away money from projects like military housing.
Reuters' recent coverage highlighted poor standards for military housing. It described that childhood infestations of mold and pests, child lead poisoning and service families were often impotent to challenge private landlords who had business deals with their military employers.
"Military housing, which was interesting ̵
"When we move through the process, we use good judgment," Shanahan said.
The step of the Republican president bypassing the Congress is trying to support the 2016 presidential campaign to build a border Wall Trump insists is necessary to curb illegal immigration.
Within hours, the lawsuit was filed in a lawsuit filed on behalf of three Texas landowners.
"We follow the law, use the rules, and we do not bend the rules," Shanahan said.
coverage of Idrees Ali aboard military aircraft; Editing by Marguerita Choy