US President Barack Obama on Sunday mourned the death of former Singaporean prime minister Lee Kuan Yew, calling him a "remarkable" man.

"I was deeply saddened to learn of the death of Singapore's minister mentor, Lee Kuan Yew," the president said in a written statement, noting he and his wife Michelle offered their "deepest condolences to the Lee family and join the people of Singapore in mourning the loss of this remarkable man."

Lee Kuan Yew, Singapore's founding father, served as the country's premier from 1959 to 1990 and then as a senior minister and minister mentor. He died early Monday local time at the age of 91.

Obama praised Lee for his efforts to build Singapore into "one of the most prosperous countries in the world today," describing him as "a devoted public servant and a remarkable leader."

"Minister Mentor Lee's views and insights on Asian dynamics and economic management were respected by many around the world, and no small number of this and past generations of world leaders have sought his advice on governance and development," he said.

The president said his discussions with Lee during a trip to Singapore in 2009 played a part in helping formulate his policy of rebalancing to the Asia-Pacific region.

"He was a true giant of history who will be remembered for generations to come as the father of modern Singapore and as one of the great strategists of Asian affairs," Obama said.