are trying to hold off gadhafi forces and on tuesday the nato commander that protecting civilians mandate extends all the way into tripoli itself. >> i think that any gadhafi forces that are demonstrating hostile intent against the libyan population are legitimate targets. >> reporter: so far the assault has cost the pentagon well over half a billion dollars, but most of that money came from cruise missiles and other munitions. the strategy has shifted and now the u.s. forces are focused on refueling planes, jamming communication and striking gadhafi forces. so the military only expects to spend $40 million over the next few weeks and a spokeswoman says after that we would incur added costs of about 40 million per month. how many months? hard to tell. >> but a stalemate is not an acceptable solution. >> i think a stalemate is not in anybody's interest. >> reporter: the nato commander told congress that he's seen flickers of terrorist elements