The US military is deploying more than 4,000 Marines and sailors to the waters around Latin America and the Caribbean as part of a ramped-up effort to combat drug cartels, two US defense officials told CNN ? a dramatic show of force that will give the president a broad range of military options should he want to target drug cartels.

The deployment of the Iwo Jima Amphibious Ready Group (ARG) and the 22nd Marine Expeditionary Unit to US Southern Command, which has not been previously reported, is part of a broader repositioning of military assets to the SOUTHCOM area of responsibility that has been underway over the last three weeks, one of the officials said.

A nuclear-powered attack submarine, additional P8 Poseidon reconnaissance aircraft, several destroyers and a guided-missile cruiser are also being allocated to US Southern Command as part of the mission, the officials said.

A third person familiar with the matter said the additional assets are ?aimed at addressing threats to US national security from specially designated narco-terrorist organizations in the region.?

On Friday, the US Navy announced the deployment of the USS Iwo Jima, the 22nd MEU, and the two other ships in the Amphibious Ready Group ? the USS Fort Lauderdale and the USS San Antonio ? but did not say where they were going.

One of the officials emphasized that the military buildup is for now mostly a show of force, aimed more at sending a message than indicative of any intention to conduct precision targeting of cartels. But it also gives US military commanders ? and the president ? a broad range of options should Trump order military action. The ARG/MEU, for example, also features an aviation combat element.

The deployment of the Marine Expeditionary Unit, however, has raised concerns among some defense officials who worry that the Marines are not trained to conduct drug interdictions and counter drug-trafficking. If that is part of their mission set, they will have to lean heavily on the Coast Guard, officials said.

MEUs have been instrumental in the past in supporting large-scale evacuation operations; a MEU was stationed for months in the eastern Mediterranean, for example, amid tensions between Israel, Hamas and Iran.

A Marine official told CNN that the MEU ?stands ready to execute lawful orders and support the combatant commanders in the needs that are requested of them.?

The US military deployed destroyers to the areas around the US-Mexico border in March to support US Northern Command?s border security mission and reinforce the US? presence in the western hemisphere. The additional assets being moved now, however, will fall under US Southern Command, and are set to support SOUTHCOM for at least the next several months, one of the officials said.

CNN previously reported that a memo signed by Defense Secretary Pete Hegseth earlier this year stated that the US military?s ?foremost priority? is to defend the homeland, and instructed the Pentagon to ?seal our borders, repel forms of invasion including unlawful mass migration, narcotics trafficking, human smuggling and trafficking, and other criminal activities, and deport illegal aliens in coordination with the Department of Homeland Security.?

The same memo also formally asked Pentagon officials for ?credible military options? to ensure unfettered American access to the Panama Canal, CNN reported at the time.

CNN?s Zachary Cohen contributed to this report.(CNN)

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