"You see how we are functioning," Prime Minister Bellerive said, showing ABC News around. "We don't have office. We don't have secretaries. We don't have cars. We don't have communications for four days."
American officials insisted that more help is coming.
At the White House, President Obama stood with former presidents Bush and Clinton Saturday and promised the ex-presidents would lead an historic fund-raising effort that would be part of a long-term commitment to rebuilding Haiti.
"If we keep doing our job," Bush said today on ABC News' "This Week," "if we hang around and do this and, you know, needle and nudge people -- and the Haitians do what they were doing before this happened, keep proving that they want to modernize the country -- I believe we can get the long-term commitment" from American donors.
Former President Clinton, who currently is the United Nations Special Envoy for Haiti, plans to travel to the beleaguered country Monday to meet with Haitian leaders and citizens, and to deliver aid, the Clinton Foundation announced Sunday.
"They want to modernize the country," Clinton told "This Week." "So what we'll do is we'll get the donors together, and we'll ask the donors to condition the release of their funds based on construction meeting certain standards and being part of a certain plan."
Other U.S. help was more immediate.
Thousands of U.S. troops already were in place and thousands more were expected ashore by next week.
Because the port facilities at Port-au-Prince have suffered major damage, the Navy was sending the salvage ship USS Grasp and a complement of construction divers.
American officials also were helping Haiti manage flights in and out of the damaged airport in Port-au-Prince.
In the longer term, the USNS Comfort, a floating hospital with a crew of 500 sailors, doctors and nurses, was expected to drop anchor outside Port-au-Prince this coming week, about nine days after Tuesday's earthquake. It has enough supplies and staff to treat 40,000 Haitians over the next several weeks, the ship's captain said.
ABC News' Richard Esposito, Jake Tapper, Kirit Radia, Jacqueline Klingebiel, Rachel Martin, Steven Portnoy, and David Kerley contributed to this report.