Former Indian-origin minister Tharman Shanmugaratnam formally launched his campaign for President of Singapore campaign and pledged to evolve the country's culture to keep it a "shining spot" in the world.
The official launch comes more than a month after Tharman first announced his intention that he will run for president.
Tharman, 66, stepped down from active politics after 22 years last month.
"I stepped into this race because I feel very strongly in the need to evolve Singapore's culture, some of our norms and the way we go about working with each other so that we remain a shining spot in the world," he said at a press conference.
He said he intended to be "a President for a new era" as he officially launched his campaign for the office.
The 2023 presidential election is due in September, as President Halimah Yacob's six-year term ends on September 13.
Accompanied by his wife Jane Yumiko Ittogi, Tharman outlined challenges facing Singapore both globally and domestically and emphasised that the nation's real challenge was to avoid becoming a divided society.
"If I'm fortunate enough to be elected as President, I pledge to bring my full experience and capabilities on the ground nationally and internationally, to serve as your President for this new and more challenging era," Channel News Asia quoted him as saying.
The senior politician said his 22 years in politics had given him ample experience in unifying people, an important role for the president.
"When we talk about being a unifying figure, I do not say this rhetorically or just as an aspiration but I speak from a real track record," he said.
"That includes the track record of respecting different views, including different political leanings and constantly trying to find common ground," he said.
Tharman said he would also fulfil other responsibilities of the presidency such as safeguarding the reserves, citing his experience in government and politics over the years.
He said he would bring a "more basic orientation" of integrity and independence of mind, which he has been known for.
"I don't have to change my colours like a chameleon. I'm the same person with the same integrity and same independence of mind, and that remains critical for the role of the president," he said.
Tharman was an economist and a civil servant, mainly at the Monetary Authority of Singapore, before joining politics in 2001.
He has served as the Minister for Education and Finance and was the Deputy Prime Minister from 2011 to 2019. He has also held prominent posts at international organisations including the International Monetary Fund, the World Economic Forum and the United Nations.
There are three prospective candidates who have publicly announced their intention to contest the polls.
The other two prospective candidates who have announced their intention to contest the election are businessman George Goh and investment manager Ng Kok Song.
Under requirements laid out in Singapore's Constitution, public sector presidential candidates must have held office for at least three years as a minister, chief justice, attorney-general or other high-level posts.
Private sector candidates must have served for at least three years as chief executives of a company with an average of Singapore dollars 500 million in shareholders' equity.
Singapore will hold its first presidential election since 2011, after President Halimah announced on May 29 that she will not seek a second term.
She is the country's eighth and first female president. Her six-year term ends on September 13 this year.
The 2017 presidential poll was a reserved election, in which only members of the Malay community were allowed to contest. Halimah was named president then as there were no other candidates.