President Donald Trump has determined that the United States is in now engaged in a formal "armed conflict" with drug cartels, which the administration has deemed as "unlawful combatants," according to a confidential memo obtained by ABC News Thursday.

It comes after recent U.S. strikes on boats in the Caribbean. 

The notice was sent to several congressional committees and was first reported by The New York Times.

This is a developing story. Please check back for updates.