The U.N. refugee agency chief says repatriation is the best solution for hundreds of thousands of Somali refugees that Kenya's government says have become a security liability. But Filippo Grandi says Kenya's time frame for the move is "very short" to put in place structures for a safe and voluntary return.

Grandi spoke Monday after visiting the sprawling Dadaab camp. Kenya says 328,000 Somali refugees there must go home by November.

The refugee chief says the refugees will need support for six months to a year, as much of war-torn Somalia lacks infrastructure to convince them to voluntarily go back home.

Grandi says most of the areas in Somalia the refugees came from are still insecure and without basic infrastructure.