KENNEBUNKPORT — President Bush ordered Defense Secretary Dick Cheney back to the tense Persian Gulf, officials said Monday, as American combat troops arriving in Saudi Arabia were told to brace for a long stay.

Bush said he would break away from his vacation for a day and return to the White House on Tuesday for deficit-reduction talks with his advisers and a briefing at the Pentagon on the military faceoff with Iraqi President Saddam Hussein.

White House press secretary Marlin Fitzwater said the naval barricade against Iraq had forced two or three ships to turn back at sea, and he declared “the embargo is being maintained” on shipping into and out of Iraq.

He also defended the inclusion of food shipments to Iraq under global sanctions, saying the purpose of the embargo is “to put the pinch on them” and deny supplies “that allow them to maintain the war machine.”

In Washington, the State Department said about 500 Americans had quietly slipped out of Kuwait in the face of Iraqi efforts to keep Westerners from leaving.

In Saudi Arabia, meanwhile, a 27-year-old sergeant stepped off a plane at a Saudi air base and summed up the concerns of many American soldiers: “Yes, it’s scary. You have to build up the courage and put the fear aside and do what you have to do.” The soldier, from Claymont, Del., had a gas mask on his belt.

“They are telling us to be ready to stay four to six months,” said the soldier. The military did not permit troops to be identified by name.

The Pentagon said Cheney will fly to Saudi Arabia on Friday to visit U.S. troops and meet with the kingdom’s leaders. It is his second trip to the Persian Gulf since Iraq invaded Kuwait on Aug. 2.

Pentagon spokesman Pete Williams said Cheney may visit other countries before returning to Washington next Tuesday. The secretary stopped in Egypt and Morocco on his earlier trip to Saudi Arabia.

Fitzwater said the Persian Gulf crisis underscored the need for a budget-cutting agreement between Congress and the White House.

“There needs to be a unity of purpose in this country not only about the conflict in the gulf but also about our spending issues and about where the budget is going,” Fitzwater said.

As global economic sanctions squeezed Iraq, the military buildup grew steadily in the Persian Gulf area. Planes carrying U.S. troops and equipment were landing about every 10 minutes, one military official said.