US defense chief says Karzai should thank allies

Panetta on Friday was responding to Karzai's recent complaints that the U.S. is failing to go after militants based in Pakistan, and instead is concentrating on the insurgents in Afghanistan.

The uncharacteristic shot from Panetta comes as tensions between the two countries have escalated over the increase in attacks in which Afghan security force members or insurgents dressed in their uniforms turn their guns on coalition troops.

Panetta's sharp retort comes just days before he and other NATO defense ministers meet in Brussels to discuss the war and the road ahead.