Aiming to cement closer ties to Laos, US President Barack Obama toured a Buddhist temple on Wednesday and paid tribute to Lao culture after pledging Washington would fulfill its "profound moral and humanitarian obligation" to clean up millions of unexploded bombs.

Obama's visit to Luang Prabang in mountainous northern Laos showcased a rich cultural and religious heritage that many in the West know little about. A UNESCO World Heritage List site along the Mekong River, the city was a hub for Buddhist faith during the Lan Xang kingdom starting in the 14th century.

Obama received a low-key reception after stepping off Air Force One and as his motorcade snaked along a dusty, paved road through town. A small cluster of people waved from shops and open air cafes, recording the spectacle on their cellphones.