In a message to mark World Refugee Day on June 20, Antonio Gutterres, the UNHCR chief, said the world community had failed to find solutions for the plight of refugees.
Guterres also delivered a powerful message for the millions of refugees and displaced people around the globe to never give up hope.
"There is one thing the international community does not know how to do properly, that is to support transition after the conflict, or a transition after a democratic system is established," Guterres said on Tuesday.
He said while Western donors are good in releasing urgent humanitarian aid, "what the international community has not been able to do is to establish a linkage between the two".
"If there is one common trait among the tens of millions of refugees that we ... have helped over the past 55 years, it's the fact that despite losing everything, they never give up hope," the former Portuguese prime minister said.
"The international community needs to devote much more attention to the transition between relief and development to rebuilding societies which have been ripped apart by violence."
Guterres said that more must be done to help countries such as Liberia avoid slipping back into chaos as they emerge from years of conflict.
Marking World Refugee Day by welcoming back civilians who fled Liberia's civil war, Guterres said millions uprooted by unrest around the world still faced a bleak future even once they returned home.
"The international community needs to devote much more attention to the transition between relief and development to rebuilding societies which have been ripped apart by violence"
UNHCR high commissioner
"Our experience shows that during the five years after a conflict is solved, half of the countries go back into conflict again," Guterres told reporters near the border between Liberia and Sierra Leone.
"Why? Because the foundations were not laid for a stable situation and for a sound economic development," he said.
The total number of refugees in the world - 8.4 million people -- is at its lowest in more than a quarter of a century, according to UN figures.
More than six million have returned home over the past four years.