The United States government wants Anthony Weiner locked up for up to 27 months for getting sexual with a minor.
Prosecutors just filed their sentencing proposal with the court ... this after Weiner copped a plea to transferring obscene material to a minor.
The government says, "This is not merely a sexting case ... With full knowledge that he was communicating with a real, 15-year-old girl, the defendant asked her to engage in sexually explicit conduct via Skype and Snapchat, where her body was on display, and where she was asked to sexually perform for him."
Prosecutors say Weiner needs a stiff sentence because his prior conduct shows he's slow to learn what he's done is wrong.
And, prosecutors say, "With that depth of awareness ... [he has] a dangerous level of denial and lack of self-control."
Sentencing is set for Sept. 25.