The Trump administration has started the arduous process of canceling $3.6 billion in military construction projects to fund its plans to build a wall along the U.S.-Mexico border.

Defense Secretary Mark Esper began notifying lawmakers Tuesday which projects will be canceled in their districts. Top Democrats immediately blasted the plan.

Senate Minority Leader Chuck Schumer, D-N.Y., was among the first lawmakers to say his district will be impacted by the funding cuts, for the U.S. Military Academy at West Point.

It is a slap in the face to the members of the Armed Forces who serve our country. - Sen. Chuck Schumer

"This decision will harm already planned, important projects intended to support our service members at military installations in New York, across the United States, and around the world," Schumer said. "It is a slap in the face to the members of the Armed Forces who serve our country that President Trump is willing to cannibalize already allocated military funding to boost his own ego and for a wall he promised Mexico would pay to build."

It is a slap in the face to the members of the Armed Forces who serve our country that @realDonaldTrump is willing to cannibalize already allocated military funding to boost his own ego, and for a wall he promised Mexico would pay to build. https://t.co/sv2ys87bw1 — Chuck Schumer (@SenSchumer) September 3, 2019

Schumer went on to say that Trump is trying to "usurp Congress's exclusive power of the purse and loot vital funds from our military." He also signaled Congress will strongly oppose any funds for new wall construction.

The Washington Post reported that Pentagon officials said they will halt 127 military construction projects to help build 175 miles of wall.

The plans come nearly seven months after Trump announced a national emergency to use roughly $8 billion to build a wall to curtail illegal immigration along the U.S. southern border. Of that, $3.6 billion was slated to come from the military construction funds, the Trump administration said during the Feb. 15 announcement.

The funds are being shifted from the Pentagon's 2019 fiscal year budget, which was approved earlier this year and runs through Sept. 30.

"President Trump's immigration efforts have failed since Day 1," said Sen. Jack Reed, D-R.I., ranking Democrat on the Senate Armed Services Committee. "Today, he made it clear he is willing to take funds from our troops and disaster victims and divert them to try to protect his political right flank. And ultimately, that could put Americans at risk."

For months, Democrats have pushed to get a list of the projects that would be held in lieu of the wall. However, the Pentagon has remained tight-lipped until this week.

Congressional sources said a full list was slated to be released Wednesday, with lawmakers learning from the Pentagon which additional projects are on the chopping block.

Reed said the diversion of funds should be legally challenged and struck down in the courts. He encouraged broad, bipartisan opposition in Congress and the courts to "misusing defense dollars."

Traditionally, the Pentagon conducts a midyear review in April to hunt down budget savings that can be moved to programs that need the money. Now, the Pentagon is redirecting funds to the wall.

Congress is usually involved in approving the reallocation of military funds, otherwise known as "reprogramming." But not this time.

Following demands from lawmakers, the Pentagon had been slated to release the list of cut military construction projects in May, but the plans were delayed.

