President Bush on Thursday condemned the hotel bombings in Jordan, saying the attackers defiled Islam and the United States would help bring those responsible to justice.

"The killings should remind all of us that there is an enemy in this world that is willing to kill innocent people, willing to bomb a wedding celebration in order to advance their cause," Bush said in the Oval Office during a meeting with President Ali Abdullah Saleh of Yemen, a Middle East ally in the war on terror.

"For those of us who love freedom and for those of us who respect every human life, no matter whether you're from the West or from your neighborhood, Mr. President, we have an obligation and a duty to remain strong and to remain firm and to bring these people to justice," Bush said.

In an Internet statement whose authenticity could not immediately be verified, Al Qaeda in Iraq linked the blasts at the Grand Hyatt, the Radisson SAS and the Days Inn hotels to the war in Iraq and called Amman the "backyard garden" for U.S. operations. The hotels, frequented by Israelis and Americans among other foreign guests, have long been on Al Qaeda's hit list.

"Today the world saw with horror the attacks on innocent people in Jordan by killers who defile a great religion," Bush said.

Bush's national security adviser, Stephen Hadley, said "our judgment is that that is a credible claim" of responsibility from Al Qaeda, but stressed the investigation is in its early stages.

Thursday afternoon, the president and his wife, Laura, went to the Jordanian Embassy in Washington to sign a condolence book for the victims.

"We have come to your embassy to express our heartfelt sympathies to the people of Jordan and to the families grieving today because of the murder of innocent people," Bush said. "This enemy must be defeated."

The president stressed that Muslims died along with Westerners in the attacks, particularly lamenting that one of the explosions occurred in a hall where 300 guests were celebrating the wedding of Ashraf Akhras and Nadia Alami, both Palestinians. They survived, but their fathers and 11 other relatives were killed.

"They have no heart. They have no conscience," Bush said of those responsible.

At least one American was among the 56 people killed in the Amman hotel bombings, a U.S. Embassy official said Thursday. The official, who spoke on condition of anonymity in accordance with embassy rules, said Wednesday's triple bombings also wounded at least two Americans. The official said the victim's name and hometown were being withheld until family was notified.

The State Department said two Americans were hospitalized, one of them seriously injured.

At the Pentagon, spokesman Bryan Whitman said officials have no indication that any Defense Department personnel were among the casualties in Amman. He said roughly 100 U.S. military personnel are based in Jordan, mainly as part of programs for training Iraqis. There has been no change in their activities as a result of the hotel bombings, he said.

Bush also called King Abdullah II Thursday to express the United States' condolences for the injuries and loss of life in the nearly simultaneous suicide attacks that also wounded more than 115 people.

Bush told Abdullah that he strongly supports his leadership and that the United States will stand with Jordan. "Both leaders agreed that it's important to reiterate to the world that the terrorists cannot shake our will and our determination to defeat their hateful, murderous ideology," White House press secretary Scott McClellan said.

The Homeland Security Department currently is not asking state and local officials to ramp up security in the wake of the Jordan explosions. The department, however, said that could change if new information becomes known indicating a credible domestic threat linked to the attacks.

The department noted that it supports local decisions to raise security measures.