The United Nations refugee agency, UNHCR, has expressed concern about the plight of the Haitian people as the country slides further into chaos.
The US has sent back some 500 Haitians picked up at sea
A UNHCR spokesman urged neighbouring countries not to repatriate refugees.
Rebels opposed to President Jean-Bertrand Aristide control nearly all major cities and have threatened to besiege the capital, Port-au-Prince.
Armed gangs loyal to the president are roaming the city's streets, looting and killing apparently innocent civilians.
The US has called on Mr Aristide to rein in his supporters.
For his part, Mr Aristide has again insisted he will not step down, despite growing international pressure for him to do so.
As the violence in Haiti shows no sign of abating and increasing numbers try to flee, the UN is calling on neighbouring countries to take in refugees until security is restored.
UNHCR spokesman Ron Redmond told the BBC World Service's Newshour programme that they were particularly concerned about the safety of people picked up at sea and forced to return.
"Not only are we asking that refugees be received by regional states, we're also recommending a suspension on any forced returns to Haiti, including those who have been rejected for asylum or picked up at sea," Mr Redmond said.
Cuba, Jamaica and Canada have said they will not send people back, but President George W Bush has warned Haitians they will be sent home if they try to flee to the US.
The US Coast Guard said it had intercepted some 500 people in boats fleeing Haiti in the past few days and sent them back.
The US is stepping up the pressure on both sides in a bid to stem the violence.
A statement issued by the American embassy on Friday called on Mr Aristide to order his supporters to stop what it called the chaos and blind violence.
The statement also urged the rebels to stop their advance to spare Port-au-Prince from further violence.
The BBC's Stephen Gibbs in the Haitian capital says the call appears to have been heeded with one of the rebels saying his current strategy is to blockade the city and thus force Mr Aristide to resign.
But the president shows no sign of leaving.
Mr Aristide says he has a responsibility to stay in office and protect his people despite the rebel gains and international pressure to step down.
The rebels now control all Haiti's major cities, with the exception of St-Marc 96km (60 miles) from the capital.
One rebel leader, Guy Philippe, has said his forces would soon be in St-Marc before entering Port-au-Prince.