WASHINGTON (AFP) - The United States on Tuesday prodded Pakistan to launch a military offensive against fighters hiding in tribal areas after Washington hinted at a lack of commitment from its ally to hunt down violent extremists. US officials said Pakistan military ruler Pervez Musharraf should send his troops into the tribal border region with Afghanistan to flush out Taliban and Al-Qaeda militants, following the collapse of a 10-month peace accord between Islamabad and tribal elders. "I think first and foremost we have to remember that some military action is necessary, and will probably have to be taken," Assistant Secretary...