Singapore Prime Minister Lee Hsien Loong said he is "grieved beyong words" over the passing away of former Prime Minister Lee Kuan Yew in his national address on Monday morning.

"The first of our founding fathers is no more. He inspired us, gave us courage, kept us together, and brought us here. He fought for our independence, built a nation where there was none, and made us proud to be Singaporeans," Lee, the first son of Lee Kuan Yew, said.

Lee Kuan Yew, one of the most influential political figures in Asia, passed away at the age of 91 Monday morning.

Lee served as Singapore's prime minister from 1959 till 1990.

"We won't see another like him," Lee Hsien Loong said.

"I am grieved beyond words at the passing of Mr Lee Kuan Yew. I know that we all feel the same way. But even as we mourn his passing, let us also honour his spirit. Let us dedicate ourselves as one people to build on his foundations, strive for his ideals, and keep Singapore exceptional and successful for many years to come."

"May Mr Lee Kuan Yew rest in peace," the prime minister added.