The U.S. government was concerned since the end of September that Western tourist sites in and around Indonesia could become targets of Al Qaeda operatives, a senior U.S. official told Fox News.
The source said U.S. officials had a list of several sites that could be targeted based on new threat information the CIA had received, and Bali was on the list.
The United States is pressing Indonesia to crack down on the Islamic militants blamed for the weekend bombing on Bali that killed nearly 200 people.
"You cannot pretend it [terrorism] doesn't exist in your country," Secretary of State Colin Powell said at a news conference Tuesday. He said he hoped the attack "reinforces Indonesia's determination to deal with this kind of threat."
Powell had announced a $50 million, three-year anti-terrorism assistance package during a visit to Indonesia in August. The Bali bombing could prompt more U.S. help along those lines.
The United States had warned last week that Indonesia was becoming a home to terrorists. And U.S. Ambassador Ralph Boyce met with Indonesian President Megawati Sukarnoputri on Tuesday to press for action terrorist groups, a senior Bush administration official said on condition of anonymity.
The official could not confirm a New York Times report that Boyce had also warned Megawati the day before the bombing that a group linked to Al Qaeda was planning an attacks in Indonesia.
President Bush said Monday that he planned to speak to Megawati. "And I hope I hear the resolve of a leader that recognizes that any time terrorists take hold in a country it is going to weaken the country itself," Bush said. "There has to be a firm and deliberate desire to find the killers before they kill somebody else."
The bombing may boost the arguments of top Pentagon officials who want to resume ties with Indonesia's military that Congress severed because of the army's atrocities against civilians.
"This is the first and most powerful recognition that the battle against terrorism is not strictly limited to the Middle East or south Asia," said Kurt Campbell, a former Pentagon adviser now with the Center for Strategic and International Studies, a nonpartisan organization that analyzes foreign policy. "Human rights worries in the short term will be overridden by national security concerns."
The car bomb that exploded on the resort island of Bali on Saturday killed more than 180 people -- most of them Australians -- and forced Indonesia's government to acknowledge for the first time that Al Qaeda is active in the southeast Asian archipelago. Some of Indonesia's neighbors, particularly Singapore, have complained that Indonesia has been reluctant to crack down on Islamic militants.
Between one and four Americans -- in addition to the two Americans killed in the blast and four others known to be injured -- remain unaccounted for, State Department spokesman Richard Boucher said. About 150 Americans are believed to have been on Bali at the time of the explosion, he said.
U.S. officials say they fear that Indonesia, the world's largest predominantly Muslim country with 210 million people, could become a breeding ground for Islamic radicalism. With more than 13,000 islands spread across 3,000 miles, there are plenty of places to hide.
Congress has passed legislation giving Indonesia's police force $16 million, including $12 million to set up a special anti-terrorism unit. The package Powell announced in August includes $400,000 to restart an exchange program for high-level military officers. Congress would have to approve the exchange program, one of the contacts forbidden after the Indonesian military's bloody suppression of dissent in now-independent East Timor.
Indonesia has a long tradition of tolerance, and the Islam practiced there is among the most moderate strains in the world. But the country has been plagued by sporadic outbursts of violence -- often involving or fanned by the military -- over religious, ethnic or other divides.
Critics say Indonesian officials have looked the other way when asked to go after Islamic extremists such as a group called Jemaah Islamiyah, which has been linked to Al Qaeda. Jemaah Islamiyah's leader, Abu Bakr Bashir, remains free in Indonesia, despite calls from Singapore, Malaysia and the United States to arrest him.
Bashir denies any links to terrorism and says Jemaah Islamiyah doesn't exist. A spokesman said Tuesday that Bashir plans to talk to Indonesian police -- who have said they do not have enough evidence to arrest him. U.S. officials say privately that Indonesia fears a political backlash if Bashir is jailed.
Indonesian authorities also inexplicably released an Islamic militant, Jafa Umar Thalib, earlier this year, just before he was to go to trial on charges of inciting violence against Christians. Thalib's group, Laskar Jihad, announced Tuesday it was disbanding.
Still, Indonesia did catch an important Al Qaeda figure in June -- Omar al-Farouq -- and gave him to U.S. authorities. He is believed to have been a liaison between Al Qaeda and Jemaah Islamiyah, involved in planning terrorist attacks in southeast Asia.
Fox News' Rita Cosby and The Associated Press contributed to this report.