IMHO, they should be labeled for what they are and seek to become. They seek to be an enemy of the US as an organized state with consulates in other nations without bilateral representation.
Congress should declare war on MS-13, then the executive branch is free to imprison any MS-13 gang member found as enemies of the US. If found operating in the US, then charge them with treason. If found guilty as MS-13 members, then condemn them to capital punishment to be executed immediately with extreme prejudice.
They are a counterculture seeking to disobey and overthrow legitimate authority.
In a sane world absolutely. This Administration, however, can't even bring itself to refer to terrorists as such what makes you think it will take a hard line against a bunch of illegal gangbangers.