The vow comes as the United States, Canada, France, Brazil and other donors with interests in Haiti meet in Montreal to map out plans to rebuild the Caribbean nation and improve aid efforts for millions of people.
The European Union, the Inter-American Development Bank, the World Bank, the IMF and several non-governmental organisations are also represented at the talks.
The “G7 will cancel all Haiti bilateral debt,” Mr Flaherty told a press conference after two days of the talks.
Haiti’s debt to the seven nations is already relatively small after being reduced by past relief efforts.
But Haiti’s foreign debt remains at about $US890 million, of which about 41 per cent is owed to the InterAmerican Development Bank and a further 27 per cent to the World Bank.
The magnitude-7.0 earthquake, which hit Haiti on January 12, is the worst recorded disaster ever to hit the Americas.