HONOLULU - US President Barack Obama called New York City Police Commissioner William Bratton on Sunday to express his condolences for the Saturday killing of two New York police officers and to offer any needed assistance, White House spokesman Eric Schultz said.

Obama's response followed an attack by 28-year-old Ismaaiyl Brinsley who allegedly walked up to the two officers in a parked squad car in Brooklyn and shot them dead.

Obama called Bratton while vacationing with his family in Kailua, Hawaii.