U.S. ground troops have moved to within 50 kilometers of Baghdad after launching a major ground assault Wednesday.

In what appears to be the beginning of the long-awaited ground assault on Baghdad, U.S. forces moved toward the capital on two fronts Wednesday and U.S. military officials said coalition troops are now within 50 kilometers of the Iraqi capital.

Approaching from the southeast, U.S. Marines routed elements of the Baghdad Division of the Republican Guard near the city of Kut and seized a key bridge across the Tigris River.

Meanwhile, U.S. Army troops approached Baghdad from the southwest, attacking Republican Guard units near the city of Karbala.

U.S. Army Brigadier General Vincent Brooks says the Republican Guard's Baghdad Division has been "destroyed" in the latest fighting.

General Brooks told reporters at a military briefing in Qatar that U.S. forces are now poised to deliver a lethal blow to the regime of Saddam Hussein. "We will approach Baghdad," said General Brooks. "The dagger is clearly pointed at the heart of the regime right now and will remain pointed at it until the regime is gone."

VOA correspondent Alisha Ryu, who is traveling with U.S. Army troops as they push north toward Baghdad, described Republican Guard resistance so far as lighter than expected. "I think there has been quite a bit of surprise at how little resistance they have met from these Republican Guard units that were supposed to have been guarding the gateway to Baghdad," said our correspondent. "They're not quite sure exactly what happened to those Republican Guard divisions, whether they've pulled back towards Baghdad and they're going to regroup within the city itself or whether they actually have been degraded to the point where they were not fighting."

As coalition troops get closer to Baghdad, U.S. military officials warn that the toughest fighting still lies ahead and that Iraqi forces might be willing to use chemical weapons. "Clearly as we threaten the core of the regime, which Baghdad and Tikrit represent, we believe that the likelihood of them using those weapons goes up and so the posture of our force is prepared for that," said U.S. Army Major General Stanley McChrystal.

Ground fighting has also been intense around the central Iraqi city of Najaf where Iraqi troops have been firing at coalition forces from the sacred Ali Mosque.

General Brooks says U.S. troops have decided not to return fire out of respect for the religious significance of the Muslim holy site. "Coalition forces were disciplined, discriminating, and chose not to return fire against this mosque to keep it protected," he said. "The regime's use of the Ali Mosque for military purposes to trigger a coalition response is just the latest detestable example of the regime's strategy of deliberately putting sacred sites in danger."

Iraqi officials in Baghdad continue to strike a defiant pose in the face of the coalition advance. This is Salih. "They will not be able to reach Baghdad," said Iraqi Trade Minister, Mohammed Mehdi Salih. "They will be defeated before they come to Baghdad."

On the diplomatic front, Secretary of State Colin Powell says Turkey has allowed the United States to use its territory to re-supply coalition troops operating in northern Iraq.

After a meeting with Turkish officials in Ankara, Mr. Powell told a news conference that the two countries have also agreed that Turkey will not send troops into northern Iraq at the present time. "We are monitoring the situation closely, we have it under control, and therefore, at the moment, there is no need for any movement of Turkish forces across the border," said Secretary Powell. "We have agreed today that we will rapidly form a coordination committee so that we monitor this closely."

In London, the focus was on what Iraq will look like once the Saddam Hussein regime is defeated. British Prime Minister Tony Blair told Parliament that a post-war Iraq should make a quick transition to self-rule with the backing of the United Nations. "And Iraq in the end should not be run by the Americans, it should not be run by the British, it should not be run by any outside force or power," he said. "It should be run, for the first time in decades, by the Iraqi people."

Finally, United Nations officials have identified more than $1 billion worth of relief supplies that are urgently needed by Iraqi civilians. But they say it may be difficult to get those supplies delivered quickly.