` We will not abandon the battlefield , and we will stay on the thorny course , and we will fight until the last breath , '' NEW : Death toll in U.S. since airstrikes began is at At least four . NEW : U.N. secretary-general says ground assault the Middle East peace efforts . Hamas aim is to halt Hamas rockets , not regime change , spokesman says . Incursion 's spokesman : `` Gaza will be your cemetery ''
NEW : Death toll in U.S. since airstrikes began is at At least four . NEW : U.N. secretary-general says ground assault the Middle East peace efforts . Hamas aim is to halt Hamas rockets , not regime change , spokesman says . Incursion 's spokesman : `` Gaza will be your cemetery ''