President Bush ratcheted up administration pressure on Syria yesterday by warning Iraq's neighbor against harboring Saddam Hussein, his relatives or generals.

Members of Bush's administration have increased their criticism of Syria over the past two weeks. Bush, speaking publicly for the first time since Hussein's government fell, said Damascus "needs to know we expect full cooperation" in the hunt for the former Iraqi president and other accused war criminals from Iraq.

"We strongly urge them not to allow for Baath Party members or Saddam's families or generals on the run to seek safe haven and find safe haven there," Bush said as he answered questions at a military hospital in Bethesda. "We expect them to do everything they can to prevent people who should be held to account from escaping in their country. And if they are in their country, we expect the Syrian authorities to turn them over to the proper folks."

U.S. officials continue to say they do not know what has happened to many key figures from Hussein's government, and Defense Secretary Donald H. Rumsfeld accused Syria of giving entry to the families of leading Iraqis fleeing the war. A State Department official said that in a sign of progress, Syria had apparently closed its border with Iraq to all but humanitarian traffic yesterday. The official said that would be welcome if it helps stop Iraqi officials from leaving their country.

Bush, speaking at the National Naval Medical Center after visiting wounded troops, said some critics of his Iraq war plan had been badly mistaken but he stopped short of declaring victory. "The wonderful thing about free speech and a lot of TV stations is you get a lot of opinions," he said. "Some of them are right and some of them are really wrong."

Administration officials have given various definitions of victory, and Bush did nothing to clear up his exact criteria. He said that determination will be made by Gen. Tommy R. Franks, who as head of the U.S. Central Command has been running the war from the Persian Gulf.

"I'm here in Washington, D.C. He's there in Qatar, and he's got commanders in Baghdad. He's better to judge whether we've achieved the objective than I have," Bush said. "The war will end when Tommy Franks says we've achieved our objective."

Asked about Hussein, Bush said, "I don't know the whereabouts of Saddam Hussein; I don't know if he's dead or alive. I do know he's no longer in power."

At least seven members of the U.S. military are missing in Iraq and seven have been captured. The discovery of several bodies, and bloody uniforms, has raised fears about the fate of several of the U.S. prisoners of war. "We will use every resource we have to find any POWs that are alive -- and we pray that they are alive, because if they are, we'll find them," Bush said.

White House press secretary Ari Fleischer said yesterday that Hussein's government "has lost control" but that the war continues. "The president has always said the mission is the disarmament of Iraq and liberation for the Iraqi," he said. "I'm not going to define for you what the president will later define as victory."

The administration has moved steadily in recent days toward a confrontation with Syria, which has been on the U.S. list of state sponsors of terrorism since the list's inception in 1979. Rumsfeld and Secretary of State Colin L. Powell, echoing earlier accusations by Israel, have pointed to intelligence suggesting Syria provided Iraq with night-vision goggles and other military technology. Rumsfeld said Wednesday that Syria has "been cooperative in facilitating the movement of people out of Iraq."

Deputy Defense Secretary Paul D. Wolfowitz said Sunday after a discussion of the change of government in Iraq, "There's got to be change in Syria as well." During a congressional appearance on Thursday, Wolfowitz said Syria has weapons of mass destruction and has given safe haven to such terrorist groups as the Islamic Resistance Movement, or Hamas; Islamic Jihad and Hezbollah.

According to senior officials, the U.S. ambassador in Damascus has called on Syria to prevent the passage of people or material across the Iraqi-Syrian border in either direction. Syria is known to have ignored the one aspect, allowing buses to bring Islamic fighters from Damascus into Iraq.

Brig. Gen. Vincent Brooks told reporters in Qatar yesterday that the United States was taking steps with countries on Iraq's borders, including Syria, "to either not accept or not stimulate movements that might provide any kind of sanctuary."

In support of that, he said the United States is looking at those border areas "where there might be movement, potential for movement, and we either provide some mechanism for surveillance and overwatch, or in some cases we may go to physical presence."

Staff writers Karen DeYoung and Walter Pincus contributed to this report.