A 22-year-old woman was stabbed to death by a woman she was arguing with across the street across from Manhattan’s Port Authority Bus Terminal, police said Wednesday.

The victim was stabbed in the chest on W. 40th St. near Eighth Ave. in Midtown about 10:15 p.m. Tuesday, cops said.

Medics rushed the victim to Bellevue Hospital but she could not be saved. Her name was not immediately released.

Her killer got away and is being sought.

It’s not yet clear to cops what sparked the argument between the two women. A man who knows the victim and was at the scene refused to cooperate with cops, police sources said.