U.S. forces have thus far been unable to fully shut down the Iraq government's ability to broadcast a television signal, a top U.S. general said Friday.

The regime of Saddam Hussein continues to use television to try to communicate with the Iraqi population despite U.S. attacks on the transmission network, said Maj. Gen. Stanley McChrystal.

McChrystal said the regime uses a combination of fixed sites and mobile vans in attempts to keep television signals intact. "It has a very redundant system," he said.

McChrystal's comments, at a Pentagon briefing, came as an image of Saddam Hussein appeared on Iraqi television, urging Iraqis to strike at the U.S.-led coalition.

"We intend to limit their ability to use those mechanisms to control the population," McChrystal said.

McChrystal, vice director of operations for the Joint Chiefs of Staff, said that of Saddam's six Republican Guard divisions, two have been destroyed, the other four "significantly degraded."

He said the U.S.-led march on Baghdad was continuing.

U.S. forces were clearing buildings at the recently seized Baghdad airport, while other units were continuing their push to Baghdad, some encountering scattered fire from Republican Guard units on the outskirts of the city.

McChrystal said that as of Friday, the United States had fired 750 cruise missiles and 14,000 precision-guided missiles in the campaign to oust Saddam's regime.

Asked about the Iraqi regime's continued ability to make use of television, McChrystal said, "The regime determined early on that one of its primary mechanisms for controlling the population and exerting coercion was through its media and it has a very redundant system."

"Clearly, we've degraded that significantly," he said. Still, Iraq still has managed to get back on the air.

As to whether Iraqis are able to see the television broadcasts, given widespread power outages, McChrystal said that Iraqi viewership was "sporadic at best."

Whether or not U.S. infantry troops push into Baghdad from their positions on the outskirts of the city, American special operations forces will continue their missions inside the Iraqi capital to undermine Saddam Hussein's regime.

U.S. forces drove Iraqi defenders from Saddam International Airport on Friday, while south of the capital, 2,500 Republican Guards surrendered to U.S. Marines, officials said. And air strikes continued, including a barrage on the headquarters of Iraq's air force.

Special operations forces were "in key locations" throughout the country, Brig. Gen. Vincent Brooks told a press conference at command headquarters in Qatar.

Pentagon officials have said U.S. commandos have been operating from inside Baghdad, as well as in the north and west of the country, since early in the war. The special forces are scouting targets for bombs or ground assaults, contacting Iraqi officials to encourage defections and perhaps trying to kill key officials or destroy important installations.

Commandos can point lasers at targets that laser-guided bombs lock onto and destroy. While those bombs can be sent off course by dust or smoke, if the tactic works it is one of the most precise ways to hit targets with the least amount of damage to civilians or their property

Although U.S. military officials have discussed few details of special forces missions in Iraq so far, Brooks also said Thursday that commandos raided one of Saddam's palaces near his hometown of Tikrit.

The American soldiers didn't find any top Iraqis but did locate documents and other material that could help in future battles and in the hunt for chemical and biological weapons, officials said.

Military officials also said coalition commandos have secured dams, bridges, airfields and oil facilities to keep Iraqis from blowing them up or using them for attacks on coalition troops or neighboring countries.

Seizure of the airport was an illustration of the tactics U.S. officials say they will use in Baghdad: taking control of key installations in quick thrusts, rather than getting bogged down in bloody, street-to-street fighting.

That's been the U.S. strategy all along -- avoiding population centers as much as possible while focusing attacks on Iraqi military and government targets. Although American troops and tanks are at the fringes of Baghdad, coalition forces still control less than half of Iraq's territory, Gen. Richard Myers, chairman of the Joint Chiefs of Staff, told a Pentagon press conference Thursday.

Military officials said the regular Army and Marine forces arriving on Baghdad's outskirts planned to form a cordon around the city, rather than trying immediately to take control of the entire city. Myers said the coalition may work to set up an interim Iraqi government during that period, making Saddam's regime irrelevant.

"When you get to the point where Baghdad is basically isolated, then what is the situation you have in the country?" Myers told reporters at the Pentagon. "You have a country that Baghdad no longer controls, that whatever's happening inside Baghdad is almost irrelevant compared to what's going on in the rest of the country."

A meeting to start forming such an interim government could take place inside Iraq within a week, a senior Pentagon official said Thursday. Intense discussions about precisely how to go about forming that interim government continue inside the Bush administration, the senior official said.