The US has announced a partial end to its arms embargo on Haiti.
UN peacekeepers have an important presence in the capital
The embargo was imposed in 1991 to prevent the army and gangs - both accused of human rights violations - from buying weapons from the US market.
President Rene Preval had complained it was hampering police efforts to fight criminal gangs.
Since Jean-Bertrand Aristide was ousted from power in 2004, Haiti has seen deadly clashes between rogue police officers, ex-rebels and gangs.
Hundreds of people in the capital, Port-au-Prince, have died in the violence, which surged when Haiti was being ruled by an interim government. Much of the violence is believed to be politically motivated.
A force of about 9,000 UN peacekeepers provides the only real security in the city.
Haiti's government will now be allowed to apply for licences to buy arms and other equipment for the police.
Mr Preval had argued that while the gangs could buy weapons on the black market, the police force could not equip itself properly.
Correspondents say the US move is a vote of confidence in Mr Preval, a former Aristide ally who was elected earlier this year.
"The United States government has taken note of the great changes in Haiti since the imposition of this embargo, namely a peaceful and democratically-elected government," US embassy spokeswoman Shaila Manyam said.
Washington imposed the embargo when Mr Aristide was overthrown the first time. When he was returned to power in 1994, his attempts to have the ban overturned were rejected by the US.