Defense Secretary Donald Rumsfeld suggested Washington had reason to believe one or more nations provided support for last week's devastating attack on America but he stopped short of saying that evidence was at hand.
Many Americans, led by Bush, who has vowed stern retaliation against any state harbouring those responsible, observed a moment of silence at 8:48 am, exactly one week after the first plane slammed into the World Trade Center.
"May God continue to bless America," he said quietly as he stood with Vice President Dick Cheney on the White House south lawn in front of the presidential residence. In a later speech in the Rose Garden, he sought to bolster American spirit as "the home front" in a war against terrorism, appealing for disaster-relief donations.
In New York, local radio and television stations stopped regular programming to play the national anthem, the sound of tolling bells or sombre music, marking the minute when the city's skyline and psyche were forever changed.
After a stinging sell-off when markets opened on Monday for the first time since the attacks, US stocks circled the unchanged mark for most of the day, as investors juggled a new-found sense of confidence and relief that Monday's sell-off proved less cataclysmic than feared, with worries of more violence and economic slump.
A tepid rebound fizzled in the late afternoon and major market gauges ended down between 0.2 per cent and 1.5 per cent -- carving out fresh three-year closing lows.
Commerce Secretary Donald Evans said Bush was considering direct financial aid to help US airlines reeling from the fallout of the aerial attacks.
Airline shares suffered the heaviest selling on Monday. With layoffs already under way, airline executives met with Transportation Secretary Norman Mineta on Tuesday to review a request for $US24 billion in government aid. Mineta said the Bush administration hoped to have an airline bailout proposal ready by early next week.
US investigators expanded to nearly 200 the number of people they want to question in connection with the attacks and are investigating if any of the 49 now in custody may have planned other hijackings.
While President Bush sought to build a strong international coalition for a possible attack on Afghanistan, which calls bin Laden a "guest," some world leaders who condemned the attacks sounded alarm bells at the prospect of American military strikes.
Washington's Nato allies have generally voiced full support for a war on terrorism, but China said any US military action should avoid harming innocent people and respect international law. State media quoted President Jiang Zemin as saying UN approval and "irrefutable evidence" were needed for China to back armed retaliation.
Egyptian President Hosni Mubarak, whose country is an important US ally in the Middle East, has also said the United States should think twice before taking military action that would kill civilians.
Germany, a key US ally, voiced caution. "We need to react with a cool head," Foreign Minister Joschka Fischer said.
But Spanish Prime Minister Jose Maria Aznar on Tuesday called for Europe's unequivocal support for the United States.
Bangladesh, a major Muslim nation in the region, said the United States could use its airspace and other facilities if it decided to launch a military offensive.
Pakistan President Pervez Musharraf was to address the nation on today as anxiety grew over expected US attacks on neighboring Afghanistan.
Reports in Pakistani newspapers raised the possibility that the Taleban could be ready for negotiations.
The Taleban might be prepared to hand over bin Laden, who is reported to have denied any hand in the attacks, under certain conditions, according to the reports in the Nation and Jang newspapers. The reports could not be independently confirmed.
The conditions included the trial of bin Laden in a neutral Islamic country, the lifting of UN sanctions against the Taleban, economic assistance and suspension of foreign aid and military supplies to the Afghan opposition, said the reports.
A senior Afghan cleric also said the Taleban would launch a "jihad" or holy war against the United States if it attacked militarily, although officials of the Islamic movement quickly said the final decision lay with a council of clerics due to convene this week.
That council on Tuesday postponed for 24 hours a discussion on the fate of bin Laden. A Pakistani delegation left the Afghan capital, Kabul, after trying to convince the Taleban it must hand over bin Laden or face a US strike.
Pakistani Foreign Ministry spokesman Riaz Khan refused to disclose details of the trip, although Taleban Information Ministry spokesman Abdul Rahman called the talks "fruitful."
Governments around the world tightened security at borders, airports and military bases.
The UN General Assembly delayed indefinitely its annual debate of world leaders set to begin next week because of the strain on New York security services from the attacks.
The International Monetary Fund and World Bank cancelled their annual meetings, which were due to be held at the end of September in Washington, because of security concerns.
The toll in the World Trade Center attack stood at 5,422 missing, with 218 confirmed dead, after six days of rescue efforts at the smoking ruins of the 110-story twin towers. Of the dead, only 152 have been identified.
A further 188 people died at the Pentagon, and 45 were killed in the crash of the fourth plane in Pennsylvania.
Caution persisted in world markets, with many financiers worried that a U.S. campaign against global terror could hit buying power worldwide.
The colossal economic consequences of the attacks have prompted Mr Bush to say he was ready to work with Congress to develop an economic stimulus package.
Along with dramatically increased security at the nation's airports, Americans are facing a range of new security measures everywhere from baseball stadiums to office high-rises.
The FBI said it was following up 47,000 potential leads. Officials have named 19 men they say used knives and box cutters to hijack the four commercial airliners.
- REUTERS
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