Two UN agencies have issued a report showing that widespread conflict in the Central African Republic (CAR) since December 2012 has caused the destruction of livelihoods, loss of food and cash crops, livestock and crucial productive assets across the country, a UN spokesman told reporters Monday.

"The unprecedented crisis in the Central African Republic is devastating the economy and people's ability to secure basic necessities," Farhan Haq, the deputy UN spokesman, said at a daily news briefing here, quoting the report by the two UN humanitarian aid agencies -- the United Nations Food and Agriculture Organization (FAO) and the World Food Programme (WFP). "FAO and WFP said the country needed a long and expensive humanitarian operation over at least the next 18 months to stem the growing toll, and pave the way to rebuild livelihoods."

UN Secretary-General Ban Ki-moon paid a visit to the CAR Saturday to focus the world's attention on a crisis that has been marked by widespread atrocities and suffering, and to call on the country's citizens to heed the lessons of neighboring Rwanda and stop the violence.

"There is a hole in the heart of Africa. Every day, I wake up thinking about your trials and troubles. Everywhere, I have called on leaders to step up their efforts," Ban said in an address to the country's National Transitional Council. "Some say this is a forgotten crisis," he said. "I am here to help make sure the world does not forget."

The secretary-general's visit came amid a recent escalation in fighting in the CAR capital, Bangui, between Christians and Muslims. The crisis, which began in December 2012, has left thousands of people dead, and 2.2 million, about half the population of CAR, in need of humanitarian aid. More than 650,000 people are still internally displaced, and more than 290,000 have fled to neighboring countries in search of refuge.