Marine Corps Commandant Gen. Robert Neller has warned Pentagon leaders that President Trump Donald John TrumpOmar fires back at Trump over rally remarks: 'This is my country' Pelosi: Trump hurrying to fill SCOTUS seat so he can repeal ObamaCare Trump mocks Biden appearance, mask use ahead of first debate MORE’s deployment of active-duty troops to the U.S.-Mexico border and transferring Defense Department funds to support the administration’s border security efforts is creating “unacceptable risk” to the service’s combat readiness.

Neller's is the strongest warning yet from a military leader about the dangers Trump’s border security efforts pose to military readiness.

In two memos sent March 18 and March 19, first obtained by the Los Angeles Times, Neller said that he has canceled or reduced planned military training in at least five countries as well as delayed badly needed base repairs due to Trump’s “unplanned/unbudgeted” border deployment last fall and emergency declaration funding efforts.

ADVERTISEMENT

The Marine Corps will not be able to participate in planned training exercises in Indonesia, Scotland and Mongolia, and will reduce participation in joint Australian and South Korean exercises, Neller wrote to Navy Secretary Richard Spencer and acting Defense Secretary Patrick Shanahan Patrick Michael ShanahanHouse Armed Services chairman expresses confidence in Esper amid aircraft carrier coronavirus crisis Boeing pleads for bailout under weight of coronavirus, 737 fallout Esper's chief of staff to depart at end of January MORE.

Neller warned that Marines “rely on the hard, realistic training” of such drills “to prepare for high-end combat,” and canceling or diminishing such exercises comes “at a time where we are attempting to double down on strengthening alliances and attracting new partners.”

Trump, shortly before the midterm elections last year, ordered active-duty troops to the U.S. southern border, claiming that a caravan of asylum-seekers traveling north from Central America was a risk to national security.

There are now roughly 6,000 military personnel currently at the border, which include 2,100 National Guard and 3,900 active duty forces.

Trump also declared a national emergency in February in an attempt to allocate funds for his promised border wall after Democrats refused to provide the full $5.7 billion he had requested for the effort.

The administration is now seeking to move about $6.1 billion from Pentagon coffers — $2.1 billion from its counterdrug efforts and $3.6 billion from military construction — to put toward building the border structure.

Neller also writes that because of the planned reprogramming he is limited in his ability to transfer money for needed repairs after hurricanes Florence and Michael, which is adding to the readiness strain.

The two hurricanes severely damaged Marine facilities and housing in North Carolina and Georgia, and the service is currently short $1.3 billion for recovery operations this year.

“The hurricane season is only three months away and we have Marines, Sailors, and civilians working in compromised structures,” Neller writes.

Congress passed a resolution that would block Trump’s emergency declaration, though the president vetoed it last week.

Following the report on Neller's memos, Senate Armed Services Committee ranking member Jack Reed John (Jack) Francis ReedWhen 'Buy American' and common sense collide Hillicon Valley: Russia 'amplifying' concerns around mail-in voting to undermine election | Facebook and Twitter take steps to limit Trump remarks on voting | Facebook to block political ads ahead of election Top Democrats press Trump to sanction Russian individuals over 2020 election interference efforts MORE (D-R.I.), said he hoped Trump would not ignore "clear warning flags" from military officials.

"President Trump has ignored the facts, ignored the experts, and ignored a big bipartisan vote against his views on boarder security. I hope he doesn’t try to ignore this memo. Decorated, senior military leaders are raising clear warning flags and trying to prevent our military from being damaged," Reed said.

Lawmakers now want to know which military construction projects would be postponed or canceled should Pentagon dollars be redirected to a wall.

The Pentagon on Monday delivered to Congress a 21-page list of military construction projects with funding that could be up for grabs, and includes everything from equipment maintenance facilities to training areas to schools for military families.

But Shanahan told the Senate Armed Services Committee that he does not yet have a “final list” of projects the Pentagon will re-appropriate money from in order to reach the $3.6 billion requested by Trump. At the time, he was awaiting a list from the Department of Homeland Security that details the projects that the Pentagon is being asked to support as part of the administration’s emergency declaration.

Shanahan sought to reassure lawmakers that using billions in military construction funding for a wall “will not come at the expense of our people, our readiness, or our modernization.”

Charles Summers, the Pentagon’s chief spokesman, said Thursday that the Department of Homeland Security has sent the Pentagon its requested list and that Shanahan is now reviewing it.

-Updated 7 p.m.