The United States sought to build support at the United Nations (UN) on Monday for the expansion of an international force to tackle Haiti's armed gangs, building on a Kenyan-led mission that Kenyan President William Ruto said has struggled with staffing and logistics.

Armed gangs have taken control of almost all of Haiti's capital Port-au-Prince in a conflict that has forced some 1.3-million people from their homes, killed thousands of people and fueled famine-level hunger.

At an event organised by the US and Kenya on the sidelines of the annual UN gathering of world leaders, Ruto said the 15-month-old force - known as the Multinational Security Support mission - had been operating at only 40% of the expected strength of 2 500 security personnel. 

The UN Security Council mandate for the MSS mission is due to expire on October 2. A Security Council resolution requires at least nine of the 15 votes in favor and no vetoes by the US, Britain, China, France or Russia. 

"I must commend the United States. They did make available logistics and vehicles. But unfortunately, most of the vehicles were second-hand vehicles, and therefore they broke down a lot, many times. And in fact, it put our personnel in great danger when they broke down in very dangerous places," Ruto said.

"But at least they stepped up," he added. "We didn't however get any useful support from any other quarter."

The United States and Panama last month put forward a draft resolution to transition the existing 15-month-old MSS mission into a new larger Gang Suppression Force supported by a new UN field office.

The proposed new force would still rely on voluntary international contributions of personnel and funding, but the leadership structure would be different. It would be led by a group of representatives from countries that have contributed personnel, plus the United States and Canada.

HAITI AT CROSSROADS

The proposal follows a US-led push last year to convert the Kenyan-led mission into a formal UN peacekeeping force to bolster its resources, which was opposed by Russia and China.

"Haiti stands at a crossroads. Port-au-Prince faces an escalating security crisis with gangs terrorising communities, extorting families and recruiting desperate children to commit horrors on behalf of gang leaders," said US Deputy Secretary of State Christopher Landau, who also announced the US was sanctioning two former Haitian officials. 

He said the MSS lacks "the mandate and the resources necessary to address the mounting scale of the challenge" in Haiti. 

China's deputy UN Ambassador Geng Shuang said Beijing supports the mission in Haiti continuing to play "its significant role and stands ready to engage with all parties to explore all possible, and also feasible, ways forward." He also said Haiti needs to "ownership and assume primary responsibility by taking concrete actions."

Laurent Saint-Cyr, president of Haiti's Transitional Presidential Council, told the event on Monday that the security situation in the country "remains the main obstacle to finalising our objective - ensuring a peaceful transition to power through elections." Haiti supports the creation of a new gang suppression force, he said.

Ruto said Kenya was ready to participate in any new mission, but warned: "If we don't correct the mistakes of the past, we will, most unlikely succeed."