Deputy Assistant Secretary of State for Caribbean Affairs and Haiti Barbara Feinstein told reporters that U.S. contributions would depend on the outcome of a Kenyan assessment expected to take place in the Haitian capital in coming weeks.

The U.S. has said it is willing to introduce a resolution at the UN Security Council to authorize such a force.

"We will be doing everything that we can to support that process and ensure swift passage of that resolution," Feinstein said.

She said the U.S. would seek contributions such as personnel, equipment, training, financing or other support from countries across the world.

Recommendations from an Aug. 15 UN report are likely to shape what the force would look like, she said.

Haiti's government requested international security assistance last year and the UN has repeatedly voiced its support for a security force.

But - wary of getting involved in a country with an unelected caretaker government and a checkered history of foreign intervention - no country had been willing to lead such an effort until Kenya said it was prepared to do so last week and committed 1,000 police officers.

Close to 200,000 people have been internally displaced in Haiti, according to recent U.N. estimates, largely in the Ouest department as residents face frequent shootings, kidnappings and sexual violence as rival gangs wage wars for territory.

Aid groups and food producers have struggled to move personnel and basic supplies to parts of the country, causing hospitals to shut and millions of people to live in famine-like conditions.

Feinstein said any U.S. assistance to Haiti's police would be provided only to vetted individuals, and that steps to withdraw this assistance would be taken in cases of human rights violations.

Broadening political inclusion and establishing conditions for free elections remained of "great urgency," she said.