JERUSALEM, ISRAEL - NOVEMBER 20: Israel&#039;s Prime Minister Benjamin Netanyahu (R) walks with U.S. Secretary of State Hillary Clinton upon her arrival to their meeting November 20, 2012 in Jerusalem, Israel. The United States signaled today that a Gaza truce could take days to achieve after Hamas, the Palestinian enclave&#039;s ruling Islamist militants, backed away from an assurance that it and Israel would stop exchanging fire within hours.