An honorary rep for the El Salvador Consulate was arrested for pointing an assault rifle at his girlfriend during a nasty argument in their posh Fifth Avenue condo, police sources said Tuesday.

Guillermo Rossell, 33, got into the fight with Lina Velasquez, 30, in their 29th-floor apartment in the Olympic Towers at 641 Fifth Ave. at around 11 p.m. Sunday, the sources said.

Rossell allegedly pinned Velasquez against a wall, picked up the rifle and pointed it at her face.

“The defendant pushed her into a wall multiple times, causing her to suffer bruising and substantial pain,” a Manhattan criminal complaint says. “The defendant pointed a gun at [her], causing her to suffer fear for her safety.”

Rossell told cops Velasquez was “throwing stuff” and “acting crazy” so he had to defend himself, sources said.