PORT-AU-PRINCE, Haiti  —  A former jurist with a reputation for honesty said Sunday he was assuming the presidency of Haiti after Jean-Bertrand Aristide (search) resigned and fled the country.

Supreme Court Chief Justice Boniface Alexandre (search), the president's constitutional successor, declared three hours after Aristide's departure that he was taking charge of the country under the constitution.

Alexandre, who is in his 60s, urged calm after more than three weeks of violence in the Caribbean nation.

"The task will not be an easy one," Alexandre said at a news conference. "Haiti is in crisis. ... It needs all its sons and daughters. No one should take justice into their own hands."

Despite Alexandre's declaration that he was in charge, the Haitian constitution calls for parliament to approve him as leader and the legislature has not met since early this year when lawmakers' terms expired.

Alexandre has been honored for his honesty in a judicial system notorious for corruption.