Germany's contribution to the military campaign is expected to be armoured vehicles designed to detect the use of chemical, biological and nuclear weapons.
Australian troops, warships, fighter aircraft and surveillance planes would also join the campaign in response to a request from President Bush, the Australian Prime Minister, John Howard, announced.
Both developments add weight to the view that plans for a ground deployment are now well advanced.
In Berlin, a flurry of half-hearted government denials and retractions followed a report in the Bild newspaper that America had asked the Chancellor, Gerhard Schröder, to dispatch Fuchs armoured vehicles to an unspecified location in "central Asia".
The Fuchs, or Fox, crewed by four technicians, is sealed from the outside world. Its electronic detectors are said to be capable of sounding an alarm within seconds of an attack involving weapons of mass destruction. Fuchs were also deployed during the Gulf War. They were on loan to the allied forces and were not manned by German soldiers.
According to Bild, Mr Schröder told leaders of parliamentary parties on Monday that Mr Bush had asked for the Fuchs vehicles during their talks in Washington last week. A government spokesman initially denied that such a "concrete" request had been made, but senior figures were less categorical as the day wore on.
"The American expectations are becoming more concrete," said Angelika Beer, the Greens' defence spokeswoman. "Without going into detail, the detection vehicle is suited to tracking down biological, chemical or atomic substances, and that would be a realistic request that the army could meet."
Other officials all but conceded that the Bild report represented a security breach. "I will not comment on it," said Joschka Fischer, the Foreign Minister. "I don't see the point of confidential briefings if they are to surface in the press."
Mr Schröder hinted that Germany's military involvement in the battlefields of central Asia was about to become "more extensive". A meeting of the Bundestag has been scheduled for early next month to approve – as the constitution demands – further deployment.
Germany has so far contributed about 50 soldiers to the crews of Awacs (airborne warning and control) aircraft dispatched from Europe to North America.
Also in the frame again are the anti-terrorist special forces, the KSK. Their initial engagement was foiled last month by press leaks. More leaks suggest that they are, after all, bound for Afghanistan, to help with search and rescue missions.
The request, meanwhile, for Australia to "activate" its pledge of military help came in an overnight telephone call from Mr Bush to Mr Howard, who announced a substantially bigger commitment than originally offered. The force will begin leaving in the next few days and will be fully deployed by mid-November.
Mr Howard said a total of 1,550 military personnel, including 150 SAS commandos, would take part in the largest overseas deployment of Australian troops in combat conditions since the Vietnam War.
Some 5,000 went to East Timor in 1999 as part of a multinational force assembled to end the violence that erupted during the independence referendum in the former Indonesian territory.
The timing of the American request reinforces expectations that the second phase of the action in Afghanistan, involving ground troops, is about to begin.
Australia joins Britain and France in contributing military personnel and hardware to the international coalition against terrorism.
Australia will also provide four FA-18A jet strike fighters, two long-range P-3 Orion surveillance aircraft and two Boeing 707 refuelling planes, as well as a guided missile frigate, two escort frigates and an amphibious command ship. Mr Howard said the destination and role was being discussed by military planners. One frigate is already in the Gulf.
Australian SAS troops won praise from their US allies during the Vietnam War for their deep reconnaissance work and ambush patrols. The Vietcong called them Ma Rung, or Phantoms of the Jungle.
In Washington, the White House expressed gratitude for Australia's support. Ari Fleischer, Mr Bush's spokesman, said the President had told Mr Howard that he "appreciated Australia's commitment to the campaign against terrorism".
Mr Howard warned Australians that the risk of casualties was high, and said SAS troops could expect to be "in the thick of" battle, possibly in hand-to-hand combat with Taliban fighters.
"It is a very dangerous operation, particularly any operation involving special forces on the ground," he said.
Kim Beazley, the leader of the opposition Labor party, backed the deployment, saying that his party stood "shoulder to shoulder" with Mr Bush and Tony Blair in fighting terrorism. "This is an appropriate commitment of Australian forces," he said.
Australia was one of the first countries to pledge support in reaction to last month's terrorist strikes on New York, Washington and Pennsylvania. It invoked Article Four of its 50-year-old military treaty with the United States, under which an attack on American territory is considered equivalent to an attack on Australia.
But the Australian Arabic Council, one of several groups representing the country's Muslim communities, warned that Australia would make itself a terrorist target by pursuing a "US/Rambo-style policy". It would become "trapped in a war that cannot be won", the council said.Reuse content