Emeritus Senior Minister Goh Chok Tong paid tribute to late South African President Nelson Mandela, saying he was "saddened by the passing of a wise leader and a great human being".
In a Facebook post on Friday from New Delhi, where he is calling on Indian leaders, Mr Goh said he had met Mr Mandela several times, and recalled his good nature.
"He harboured no rancour, no bitterness. He loved people, regardless of their colours. He always had a smile, a laugh and a twinkle in his eyes," said Mr Goh in his post, adding that he would be sending a formal letter of condolence to Mr Mandela's wife and family upon his return to Singapore on Saturday.
Mr Goh added that he was following the news on Mr Mandela's death from his hotel room in New Delhi.
He recalled their first meeting in 1991 in Harare, Zimbabwe, during the Commonwealth Heads of Government (CHOGM) meeting. Mr Mandela had just been released from prison then, after spending 27 years in jail, for his opposition to white minority rule in South Africa .
"As president of ANC, he sought Singapore's help. I visited him officially in Pretoria soon after he became president," ESM Goh said.
"I took the opportunity... to go to Robben Island to see his cell and understand better the conditions which played a part in shaping his character and leadership qualities.
"We met also a few more times at CHOGM and in Singapore when he visited."
Mr Mandela visited Singapore in March 1997, in the first state visit by a South African head of state.
He died peacefully at his Johannesburg home on early Friday morning, Singapore time, after a prolonged lung infection. He was 95.