In a speech at Gaza's Islamic University, Hamas leader Abdel Aziz Rantisi said he was not surprised that the United States vetoed a U.N. Security Council resolution condemning Israel's assassination on Monday of Hamas spiritual leader Sheik Ahmed Yassin.
"We knew that Bush is the enemy of God, the enemy of Islam and Muslims. America declared war against God. Sharon declared war against God and God declared war against America, Bush and Sharon," Rantisi said. "The war of God continues against them and I can see the victory coming up from the land of Palestine by the hand of Hamas."
Despite the harsh rhetoric, Rantisi has backed away from Hamas threats to carry out revenge attacks against the United States in response to the assassination.
But this kind of rhetoric could serve as inspiration for other Islamic militant groups - such as al Qaeda - to strike at America, reports CBS News Correspondent Robert Berger.
The United States lists Hamas as a terrorist organization. The militant group has carried out many of the suicide bombings that have killed more than 450 people in the current conflict between Israel and the Palestinians.
In other major developments in the Middle East:
Israel is taking the Hamas threats seriously, including statements that Sharon and other Israeli officials are legitimate targets.
Israel has increased security and assigned armored Cadillacs to several Cabinet ministers, one minister said on condition of anonymity. The minister refused to say how many armored cars were provided, but said Likud Party hard-liner, Gideon Ezra, was among those who received one.
In the past, Finance Minister Benjamin Netanyahu, a former prime minister, used an armored car on occasion. The only government officials who regularly drive in armored cars are Sharon and Defense Minister Shaul Mofaz.
Since Yassin's assassination, Israeli has tightened security measures. Israeli border patrol, troops and police have been sent into the streets, setting up roadblocks and checking IDs randomly. Cafes, buses and malls emptied out for several days as Israelis braced for retaliation.
Nine Israeli lawmakers have been given 24-hour protection, among them Likud hard-liners Yuval Steinitz and Ehud Yatom.
Rabbis, including Israel's current and former chief rabbis, have been assigned security guards, said a security official, who spoke on condition of anonymity.
Rabbi Ovadia Yosef, a prominent religious leader and founder of the ultra-Orthodox Shas party, moved his weekly Saturday night Bible study class to a secret location due to reported intelligence warnings that militants are targeting rabbis.
Chief of Staff Lt. Gen. Moshe Yaalon and other senior generals have also been assigned additional bodyguards, officials said.
Israel's Foreign Ministry increased security at embassies, consulates and missions abroad following the assassination. Israeli diplomats at missions in Qatar and Mauritania were brought home a week earlier than scheduled for the Jewish holiday of Passover.
In a West Bank village near Hebron, Israeli soldiers shot and killed a Palestinian fugitive during an arrest operation Sunday, the army said. The fugitive, Jamal Atel, was a member of the Al Aqsa Martyrs' Brigades, a militant group linked to Yasser Arafat's Fatah movement. Atel fled to the roof of his house when the army came to arrest him, and soldiers shot and killed him, the army said.