US Secretary of State Colin Powell says Washington will help the Haitian people and leadership make a new beginning.
Powell's visit is the first by a senior US official since Aristide left
Mr Powell was speaking during a visit to Haiti to show support for the interim government installed after President Aristide was forced out.
He also rejected a call by the Caribbean community for the UN to investigate Mr Aristide's departure.
Meanwhile, the interim administration has announced that political parties have agreed to hold elections in 2005.
Mr Powell's visit comes more than a month after President Jean-Bertrand Aristide was forced from power and a multinational force was sent to restore order.
Mr Aristide, currently in Jamaica, says he was kidnapped by the US and has launched a lawsuit.
The organisation of Caribbean states, Caricom, has refused to recognise the new government in Haiti and demanded a UN inquiry into Mr Aristide's departure.
But Mr Powell told a news conference in Port-au-Prince that the ex-president's flight into exile had prevented a "bloodbath" and no purpose would be served by an investigation.
Haiti now had the chance of a new beginning, he said.
"I urge the proud people of Haiti to come together in peace, to seize this new chance to put your country firmly on the path to democracy."
Appearing alongside Mr Powell, the interim prime minister Gerard Latortue said elections would take place in 2005.
That is longer than the 90 days allowed for in the Haitian constitution but Mr Latortue said everyone had agreed it was not possible to hold a poll any earlier.
He appealed for US help in everything from getting the economy moving to collecting the rubbish.
"The country is in a state of total bankruptcy," Mr Latortue said. "Those who were here before left the country with absolutely nothing."
Mr Powell also met some of the 2,000 American soldiers who make up the bulk of the 3,600-strong UN-backed force, which also includes troops from France, Chile and Canada.
Washington was hoping a new stabilisation force, made up largely of peacekeepers or police from the Caribbean and Latin America, would replace them in early June.
But the plans were thrown into doubt when Haiti's Caribbean neighbours declared they would not recognise Haiti's new government.
Mr Aristide was flown out of Haiti on 29 February after an insurgency by armed rebels who advanced across the country.