The United States welcomed Israel's ceasefire in the Gaza Strip and said it expected all parties to stop hostile actions immediately while the United Nations expressed relief.
Iran said the ceasefire was not enough and that Israel's military must withdraw, whereas the pope urged the world to pray for peace in Gaza and the hundreds killed in the conflict.
"The goal remains a durable and fully respected ceasefire that will lead to stabilization and normalization in Gaza," Secretary of State Condoleezza Rice said after Israel called off its three-week offensive in the area.
"The United States commends Egypt for its efforts and remains deeply concerned by the suffering of innocent Palestinians," she added. "We welcome calls for immediate coordinated international action to increase assistance flows and will contribute to such efforts."
Hailing the ceasefire
U.S. President-elect Barack Obama welcomed Israel's ceasefire and will say more on the situation in Gaza after he is inaugurated on Tuesday, his spokeswoman said.
Hamas announced an immediate ceasefire by its fighters and allied groups in Gaza on Sunday, senior Hamas official Ayman Taha told Reuters, adding that the Islamists gave Israel a week to pull out its troops.
U.N. Secretary-General Ban Ki-moon welcomed the Israeli ceasefire and urged Israel to withdraw all of its troops.
"I am relieved that the Israeli government has decided to cease hostilities," Ban told reporters. "This should be the first step leading to the full withdrawal of Israeli troops from Gaza," he said, adding he wanted the withdrawal "as soon as possible".
He said Hamas gunmen also needed to do their part to bring an end to the violence by halting their rocket attacks against southern Israel. "Hamas militants must stop firing rockets now," he said.
European leaders and Ban attended talks in Egypt on Sunday aimed at bolstering the ceasefire.
Victory of Islamic resistance
Israel declared a unilateral ceasefire which took effect at 2 a.m. (0000 GMT) on Sunday. Within hours, five rockets were fired at the Israeli town of Sderot, causing no casualties. Hamas announced its ceasefire later on Sunday.
Iran's Foreign Minister Manouchehr Mottaki said the ceasefire announcement showed the "victory of the Islamic resistance and the heroic people of Gaza" against Israel, the official IRNA news agency reported.
"The mere halt in air, sea and land attacks, without the withdrawal of the (Israeli) forces from the occupied positions, would not be enough for the cessation of confrontation," Mottaki said. "It is necessary that the Zionist forces leave the occupied regions," he said, calling their presence "provocative".
Pope Benedict, in his strongest comments yet on the situation in Gaza, on Sunday condemned the violence that he said had killed hundreds of "innocent victims".
Speaking at his weekly Sunday noon prayer, the pope also asked his listeners in St Peter's Square and around the world to pray for the success of all efforts "to end the tragedy" and bring about lasting peace.