WASHINGTON - US Vice President Dick Cheney said Sunday Israel did not consult the United States before invading Gaza. Cheney, in an appearance on CBS's "Face the Nation," defended the Israeli ground campaign. He described Israel as a "U.N. member state being attacked by a terrorist organization." Israel's ground troops, backed by gunships and tanks, on Saturday night launched an invasion into the Gaza Strip. Reports here quoted Palestinian security sources as saying that the troops have gained control of the eastern section of the northern Gaza Strip throughout Sunday. The strikes lasting eight days in the Gaza Strip have killed some 480 people, mostly Palestinian militants, and wounded 2,800 others. For the Israeli side, four people have been killed in the ongoing rocket attacks by Hamas and other Palestinian militants from the Gaza Strip. "I think it's important to remember who the enemy is here," Cheney said. "The enemy is not the Palestinians, from the perspective of the Israelis -- it's Hamas." Cheney said his remarks on Israel's motives were "informed speculation." "They didn't seek clearance or approval from us, certainly," he said. The vice president said Israel does not want to return to the situation where Hamas continually fired rockets into Israel from Gaza. Cheney also defended the Bush administration's domestic surveillance programme."I don't believe we violated anybody's civil liberties," he responded when asked if the administration had gone too far.