President Tony Tan Keng Yam and his wife, Mrs Mary Tan, sent their birthday wishes to former Prime Minister Lee Kuan Yew, who turned 90 on Sept 16.

Dr Tan wrote on his Facebook page that generations of Singaporeans have benefited from Mr Lee Kuan Yew's lifelong contributions towards creating the peaceful and prosperous Singapore that we know today.

"Mr Lee reminds us that Singapore is a constant work in progress as he continues to work tirelessly to secure our future even after more than five decades of public service," he wrote.

He added: "Mary and I wish Mr Lee joy and continued good health on his 90th birthday."