Former Supreme Court chief justice Mr Boniface Alexandre was formally installed as the new Haitian president on Monday in a ceremony at the National Palace, which is under heavy guard by foreign troops.
Mr Alexandre was sworn in as president behind closed doors on February 29th, hours after Jean-Bertrand Aristide was sent into exile in Africa, US and Haitian officials said.
The ceremony at the palace was a formalisation of his presidency important to the Haitian people, US officials said.
In a speech during the ceremony, Mr Alexandre called for national reconciliation and new elections.
The ceremony took place a day after six people were killed in Port-au-Prince when gunmen opened fire on a crowd of thousands of Haitians celebrating Aristide's departure.
US Marines have been guarding the National Palace since Mr Aristide fled at dawn eight days ago, forced from office by international pressure and a month-long rebellion in which more than 200 people have been killed.