This picture taken on August 28, 2019 shows a portion of the wall on the US-Mexico border seen from Chihuahua State in Mexico.
CNN  — 

The Defense Department, under White House pressure, is expected to announce this week that billions more in Pentagon funds will go toward the border wall, according to an administration official.

A senior Defense official also told CNN that a major announcement about the border will made this week.

While the White House is poised to ask for less money for the wall in the upcoming formal budget request to Congress, the administration appears to be increasingly relying on Pentagon funds to meet its goal of constructing additional barriers on the border. The Trump administration has argued that it does not need congressional approval to redirect military funds to the border wall.

Last year, Trump declared a national emergency, allowing him to unlock billions of dollars in federal funds to mount additional barriers along the US-Mexico border. While efforts to pull from several government accounts has been met with legal challenges, the administration has pressed forward.

In January, the Pentagon received a request from the Department of Homeland Security to build and pay for hundreds of additional miles on the southwest border.

The request is for roughly 270 miles of border barrier and other infrastructure to be built in areas that are considered drug corridors, a mix of rural and urban areas, a senior Department of Defense official told CNN at the time.

Because the request is to ostensibly help combat drug smuggling, the Pentagon will be allowed to construct those barriers under its pre-existing “284” counter drug authority, which allows the Defense Department to build barriers, lighting and roads for the purpose of countering drug trafficking, according to the official.

The official said that following the completion of a Pentagon assessment of the request, Secretary of Defense Mark Esper would make a determination to approve all, some or none of the request.

It was not immediately clear Sunday whether Esper had formally green lit the latest request, but one official said that his approval was expected this week.

The Defense Department did not immediately respond to a request for comment.

$2 billion expected ask from Congress

The White House is set to ask Congress in its forthcoming budget proposal for less border wall funding than in previous years, a White House official said.

The budget proposal, expected to be released this week, requests just $2 billion for the construction of a wall. Last year, the White House initially asked for $5 billion, which it did not get from Congress. It has asked for as much as $8.6 billion in prior requests.

The Wall Street Journal first reported the anticipated Trump administration request.

While the number in the coming budget is lower than what the Trump administration has requested previously, it is still higher than what lawmakers have provided for wall funding in the past. The spending deal struck by Congress in December kept wall funding at the same level – less than $1.4 billion – that was set aside for the wall the previous year.

Funding for the border wall has been a major sticking point in appropriations talks between the administration and Congress.

In 2018, President Donald Trump allowed the government to shut down for a historically long impasse that did not yield him the requested money for his wall. Since then, the White House has explored different ways of paying for the wall, such as diverting funds from military construction projects.