"The people of Haiti need action to address urgent humanitarian needs," Guterres told reporters at the UN headquarters.
According to the UN chief, the UN humanitarian response plan, which requires 720 million U.S. dollars to help more than 3 million people in Haiti, is only 23 percent funded.
"I appeal to the world to extend a lifeline of support and fill that financial gap without delay," he said.
Guterres, who recently visited Port-au-Prince, the Haitian capital, described the situation in Haiti as "largely a forgotten crisis despite its severity."
"The Haitian people are trapped in a living nightmare. Humanitarian conditions are beyond appalling," he said, adding that brutal gangs have a stranglehold on the people of Haiti.
Guterres called on UN Security Council members and relevant potential contributing countries to "act now" to create the conditions for the deployment of a multinational force to assist the Haitian National Police.
He also urged all social and political actors in Haiti to accelerate their efforts toward a desperately needed political solution.
Conditions are desperate, but solutions are possible in Haiti, Guterres said, underscoring the need to take simultaneous actions.
"We cannot forget the Haitian people. The world must step up," he said.