Hadiya Pendleton was killed in a park by a gunman who was not even aiming at her as she talked with her friends.
Chicago police said Hadiya, who was in a marching band at this month's inauguration, was in a park about a mile from Mr Obama's home on Tuesday afternoon when a man opened fire on the group.
Hadiya was shot in the back as she tried to escape.
White House press secretary Jay Carney said the president and first lady Michelle Obama's thoughts and prayers were with Hadiya's family, adding: "And as the president has said, we will never be able to eradicate every act of evil in this country, but if we can save any one child's life, we have an obligation to try when it comes to the scourge of gun violence."
The city's 42nd killing is part of Chicago's bloodiest January in more than a decade, following 2012, which ended with more than 500 murders for the first time since 2008.
It also comes at a time when Mr Obama, spurred by the Connecticut school massacre in December, is actively pushing for tougher gun laws.
Hadiya's father Nathaniel Pendleton spoke at a Chicago police news conference yesterday, held at the park where his daughter died.
"He took the light of my life," Mr Pendleton said, then spoke directly to the killer, said: "Look at yourself, know that you took a bright person, an innocent person, a non-violent person."
About three streets from Hadiya's school, she and a group of 10-12 young people had taken refuge under a canopy to avoid the rain. A man climbed a fence, ran at the group and started shooting before fleeing
Hadiya was shot once in the back and a teenage boy was shot in the leg.