SINGAPORE - In the very first hours of Singapore's independence 52 years ago, founding prime minister Lee Kuan Yew pledged that Singapore "would not be a Malay nation, a Chinese nation nor an Indian nation".

On Thursday (Sept 13), Singapore renewed this promise to build a multiracial, multicultural and multi-religious society, as Madam Halimah Yacob was sworn in as the country's first Malay president in 47 years, and the first Malay to be elected president since it became an elected office in 1991, said Prime Minister Lee Hsien Loong.

She is also Singapore's first woman head of state, he added as he uttered to applause the words "Madam President" in a speech during her inaguration at the Istana.

Describing this as a significant moment in Singapore's history, PM Lee said: "Today, we reaffirm the pledge that Mr Lee Kuan Yew made on August 9, 1965... Everybody would have his place, equal, regardless of language, culture, religion."

When this pledge was made, Singapore had a Malay head of state.

Mr Yusof Ishak was Yang di-Pertuan Negara from 1959 and became Singapore's first president after its expulsion from Malaysia in 1965. He died in office in 1970, at the age of 60.

"President Yusof Ishak symbolised, visibly, that though we had been forced out of Malaysia primarily because we were a Chinese-majority city, independent Singapore would never in turn suppress its own non-Chinese minorities," said PM Lee. "We chose the nobler dream: A multi-racial, multi-religious Singapore."

Half a century later, Madam Halimah's rise to the highest office in the land symbolises, visibly, that Singapore will persevere with this dream, he added, and this has become all the more urgent, considering the trends playing out regionally and globally.

"In an age when ethnic nationalism is rising, extremist terrorism sows distrust and fear, and exclusivist ideologies deepen communal and religious fault lines, here in Singapore we will resist this tide," said PM Lee.

"Here, the majority will make extra efforts to ensure that minorities enjoy equal rights. That is something special, precious and fragile. That is why we make sure that Parliament always has representatives from all ethnic groups."

He added that Singapore will now regularly have a head of state, the symbol of the nation, who "can look like President Benjamin Sheares, a Eurasian; President SR Nathan, an Indian; President Tony Tan Keng Yam, a Chinese; and President Halimah Yacob, a Malay and a woman".

This was the "compelling reason" for the amendment of the Constitution last year, he said referring to the introduction of the reserved presidential election to ensure that members of all communities have a chance to be president from time to time.

An election is reserved for candidates from a particular community if no one from the community has held the office of president in the last five terms.

"Madam President, Encik Yusof Ishak was President of all Singaporeans, regardless of race, language, religion or gender," said Mr Lee. "You too will unify all of us. You too will strengthen our sense of nationhood. You too will be our President."

Madam Halimah - a PAP stalwart who quit her political and party posts in August to contest the presidential election - has been in the public service for four decades.

This wealth of experience has prepared her for her new duties as custodian over the nation's past reserves and key public service appointments, said Mr Lee.

On these issues, Madam Halimah will have to make independent judgments, tapping on the experience and advice of her Council of Presidential Advisers, but must at the same time work closely with the Government for the two-key mechanism to function properly, he added.

"I look forward to establishing such a relationship with you, just as I did with your predecessors," he said.

PM Lee also said that there is one significant difference between being President and Madam Halimah's previous posts.

"Hitherto, you have been fighting the good fight - in the unions, in the political arena, in the governing party. Now as President, you have to be non-partisan and above the political fray," he said.

The President is the symbol of the nation, and in this role, Madam Halimah has to be the nation's unifying figure, and represent all Singaporeans, he added.

"I am confident that you will adapt to this new role, and perform it with distinction," he said.

Madam Halimah brings to the presidency a heartfelt concern for her fellow citizens, a strong sense of duty, and a sterling record of public service, he said as he paid tribute to her track record of serving the people.

As a unionist she championed workers' interests, and as a social activist and community leader cared for the underprivileged and the needy, added Mr Lee.

When she joined politics in 2001, Madam Halimah did not let up on looking out for people.

As MP, she worked with residents to solve their problems and brought people together to build a community, the Prime Minister said.

When she became Minister of State in 2011, she worked with youth groups, improved childcare services to support working mothers, and enhanced support for the disabled by setting up the Centre for Enabled Living, which later became SG Enable.

She was elected Speaker of Parliament in 2013, and was even-handed and fair to all MPs, encouraging robust debates on national issues, added Mr Lee.

Along the way, Madam Halimah had overcome difficult challenges in life.

Briefly recounting her life story, PM Lee said it is a reflection of the Singapore story.

Madam Halimah's father died when she was eight and she had to juggle studies with work before eventually becoming the first in her family to make it to university, and devoting decades of her life to public service.

"In time you achieved success, but you never forgot the poverty of your childhood. You went out of your way to help those in need, and enable many others to succeed as you yourself have done," said PM Lee.

He added: "Your life story symbolises the sort of society that we aspire to be, and reminds us that the Singapore story is one of hope and opportunity. In Singapore, no matter where we begin in life, if we work hard, we will have ample chances to do well; and when we make good, we have a responsibility in turn to help others around us."