By the end of Monday, 5,200 active borderline service members will be working in an officially supported Customs and Borders Support (CBP) mission, but on the eve of the midterm election, President Trump continues to use the campaign as a campaign issue.
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"I noticed that all this beautiful barbed wire came up today," said Trump at a Montana campaign on Sunday. "Using barbed wire properly can be a beautiful sight."
The president referred to soldiers on active duty who lay accordion cables at a Texas border crossing over the weekend. The move was in line with the Customs and Border Assistance Support Mission provided by US Northern Command.
On Monday, however, Trump gave the impression that the activists assigned to Operation Faithful Patriot were playing a more visible role.
"Barbed wire looks like it's very effective with soldiers standing in front of it," Trump said to a campaign rally in Cleveland.
Operation Faithful Patriot, however, is supposed to be a mission in which the active troops only support CBP, as they are legally prohibited from prosecuting law enforcement.
General Joseph Dunford has reiterated the purpose of the mission on Monday night at Duke University.
"It is not planned that the US Forces will be included in the actual mission of denying entry to the United States," said Dunford. "There is no plan for the soldiers to come into contact with immigrants or to strengthen the Department of Homeland Security in carrying out their mission, we offer the opportunity."
For this purpose, construction and construction units will be erected at the border crossing points for vehicle barriers and fencing, as well as temporary housing for the CBP staff, who will be sent to the border. Helicopter units are also deployed to transport CBP personnel to Hart to reach border regions, officials said.
A Pentagon spokesman said Monday that the installation of accordion wire was in line with the mission to help CBP close gaps in the ports of entry along the border.
"They tell us which points are vulnerable," said Colonel Rob Manning.
President Trump also left comments last week raising the question of when military forces might be allowed to fire their weapons.
"They want to throw stones at our military, our military will fight back … we'll consider that as a firearm," he said on Thursday.
Trump changed his posture the following day.
"They'll do it to us, they'll get arrested, there'll be trouble, I did not say, shoot, I did not say, shoot, but they'll do it, they'll arrest us, we'll arrest them," he said Reporters who had asked for clarification.
The Pentagon recognizes that members of the military service have the right to self-defense, but does not publish the standards for using force except to say that they are proportionate.
Col. Manning declined to discuss a hypothetical situation with reporters on Monday. However, he made it clear that only military police should be armed along the border as they provide protection to other military units.
The Pentagon estimates there will be 5,200 active forces by the end of Monday in Arizona, California and Texas, with numbers expected to rise to over 7,000 in the coming days.
The majority of the armed forces are currently in Texas, where 2,600 service members arrived last week. There are 1,100 service members in Arizona and California.
This number will rise to over 7,000 in the coming days.
Building units have begun building temporary military tent tent shelters in some of the major bases that serve as a site.
Last week, President Trump described "massive tent cities" built by the military and said he would accept migrants seeking asylum. The military, however, emphasized that the temporary tents would only serve to accommodate additional CBP personnel sent to the border.
ABC News has learned, however, that the Department of Homeland Security (DHS) had filed a first petition to the Pentagon to deport migrants arrested along the border in tent structures, according to a US official.
The initial DHS request was not accepted early by the Pentagon and was not forwarded in the chain of command for approval.
The official pointed out that the request was different from a previously approved DHS request this year, which said that migrant families should continue to be housed at military bases in the immigration process.
Reuters initially reported that the Pentagon had argued at the Homeland Security Department's first request.
Asked about the Reuters report, Manning refused to comment on internal deliberations between the Department of Defense "and our interagency partners." Captain Bill Speaks, another Pentagon spokesman, added, "We have not been requested by the DHS to build facilities for migrant families."
Trump said he plans to pitch tents to house migrants detained in these facilities while the US government weighs their asylum application.
Manning also clarified that the Military Police (MP) will be the only active forces armed during the operation. The border mission has been assigned MP units to forcibly protect the units that logistically support CBP.
There is still no official cost estimate for the 45-day mission, but Manning said the Department of Defense will "absorb" the cost of the operation.
"The cost will be determined by our comptroller, and if we can provide it, we will do that," Manning said.