President Donald Trump is deploying 700 active-duty Marines to quell the anti-deportation protests erupting in Los Angeles — but the order is so unprecedented, Pentagon officials are being forced to write the rules for the deployment as they go, The Associated Press reported on Monday.

"The 2nd Battalion, 7th Marines are coming from Twentynine Palms, California, and will augment about 4,100 National Guard members already in LA or authorized to be deployed there to respond to the protests," reported Tara Copp and Lolita C. Baldor. However, while "the forces have been trained in deescalation, crowd control and standing rules for the use of force" per the Northern Command, uncertainty remains about whether they are prepared for this type of assignment deployed against Americans.

"The Marines are highly trained in combat and crisis response, with time in conflict zones like Syria and Afghanistan," the report continued. Nonetheless, "that is starkly different from the role they will face now: They could potentially be hit by protesters carrying gas canisters and have to quickly decide how to respond or face decisions about protecting an immigration enforcement agent from crowds."

The troops are not bound by the standard overseas rules of engagement that determine how they can respond to threats, the report continued. Here, the Northern Command has to set up its own rules governing force, "and then each Marine should receive a card explaining what they can and cannot do, another U.S. official said." Per documents obtained by AP, the Marines would not be allowed to use warning shots, and would be instructed to de-escalate conflict whenever it can be done safely.

All of this is coming after Trump moved to federalize the National Guard against the protests — which California Gov. Gavin Newsom said was done under deceptive pretenses and is preparing legal action to challenge.

Trump, for his part, has ramped up his rhetoric and threats against the protesters, saying that anyone who spits at federal authorities will be subject to beatings.