Pentagon officials say they are sticking to the priority of pressing towards Baghdad, despite the persistence of resistance in the south of the country.
Apache helicopters' initial assault has only been a partial success
But it is unclear when the push towards the Iraqi capital will be renewed, and it may be delayed several days at least.
Any hopes that the Iraqi authorities might have crumbled in the face of the Americans' rapid early advance and heavy initial air strikes seem to have evaporated.
At the Pentagon, Vice Director of Operations for the Joint Staff, Major General Stanley McChrystal, said the continued skirmishing in the south had been fairly limited and had not put the US-led forces off their plan.
Still, some Pentagon officials have conceded that the resistance has been greater than expected, and that they were making adjustments.
The continued fighting has fuelled criticism from analysts and retired senior military officers that the initial US-led invasion force was too small and lacking sufficient firepower.
The "rolling start" of launching the attack while other forces continued to arrive has also been criticised.
Part of the plan appears to have been to make up for the relative lack of numbers on the ground with scores of powerful Apache attack helicopters.
But their initial assault appears to have been, at best, only a partial success.
And since then the weather has grounded this force.
'Softening' Iraqi forces
Another missing element until now has been a significant northern front.
Weather conditions have hampered coalition troops in southern Iraq
That is changing with the arrival of the first 1,000 troops of the 173rd Airborne Brigade, parachuted in to a northern Iraqi airfield.
More troops and equipment will be airlifted in, including tanks.
This is still not the northern option that the Pentagon would have preferred, as the forces are smaller and lighter than originally planned.
But at the very least they could "fix" Iraqi forces in the north, and prevent them heading south to reinforce Baghdad.
Delaying a further push from the south will allow more time for the Republican Guard divisions around Baghdad to be "softened up" from the air.
But the Iraqis may still choose to take the initiative.
The US-led forces will be hoping that a decisive engagement with the southern defences of Baghdad will force the collapse of Saddam Hussein's grip on power before they have to confront the issue of moving in to Baghdad itself.
At the same time, reinforcements continue to flow.
The Fourth Infantry Division, the force originally earmarked for the northern front through Turkey, is to begin deploying to Kuwait.
Its equipment is already on the way from the eastern Mediterranean, where it had been packed aboard ships awaiting a Turkish decision.
It will be two or three weeks before that division is ready to join the fight.
But where exactly the campaign will be by then is not clear.