World leaders praised Lee Kuan Yew, who died Monday at the age of 91, as a visionary statesman whose confidence and insight helped build Singapore into a prosperous and influential nation. Their tributes arrived as Singapore declared a week of national mourning to mark the death of the city-state’s founding father.

Singapore’s current prime minister, Lee Hsien Loong, the son of Lee Kuan Yew, said during a televised address Monday morning that his father "fought for our independence, built a nation where there was none, and made us proud to be Singaporeans.

"Singapore was his abiding passion,” his son said. "He gave of himself, in full measure, to Singapore. As he himself put it towards the end of his life: ‘I have spent my life, so much of it, building up this country. There is nothing more that I need to do. At the end of the day, what have I got? A successful Singapore. What have I given up? My life.’”

The former leader’s body will lie in state at the Parliament House from Wednesday through Saturday, and a state funeral will be Sunday.

Lee Kuan Yew led Singapore from 1959, through its tumultuous separation from Malaysia in 1965, and remained at the helm until 1990, an era in which it rose "From Third World to First,” as he titled his 2000 book on the former British colony’s modern history. He remained an influential figure in local and world affairs for more than two decades after stepping In a statement, President Obama called Mr. Lee "a visionary who led his country from Singapore’s independence in 1965 to build one of the most prosperous countries in the world today.” He thanked Mr. Lee for advice he gave during his 2009 trip to Singapore, which Mr. Obama said was important as he developed a policy of American rebalancing toward Asia.

"He was a true giant of history who will be remembered for generations to come as the father of modern Singapore and as one the great strategists of Asian affairs,” Mr. Obama said.

China, which has at times looked to Singapore as model of Asian prosperity with little corruption and constrained politics, also spoke of Mr. Lee’s guidance. The Chinese Foreign Ministry spokesman Hong Lei called him "a uniquely influential statesman in Asia and a strategist boasting oriental values and international vision.”

Prime Minister David Cameron of Britain said Mr. Lee "was always a friend to Britain, if sometimes a critical one, and many British prime ministers benefited from his wise advice, including me.”

Mr. Cameron said that Margaret Thatcher, the former British prime minister, said "there was no prime minister she admired more than Mr. Lee for ‘the strength of his convictions, the clarity of his views, the directness of his speech and his vision of the way ahead.’”

"Lee Kuan Yew was a legendary figure in Asia, widely respected for his strong leadership and statesmanship,” said a statement from the spokesman for Ban Ki-moon, the secretary general of the United Nations. "During his three decades in office, he helped Singapore to transition from a developing country to one of the most developed in the world, transforming it into a thriving international business hub.”

Singapore’s neighbor Malaysia also praised Mr. Lee. "I pay tribute to Mr. Lee Kuan Yew’s determination in developing Singapore from a new nation to the modern and dynamic city we see today,” said Prime Minister Najib Razak. "His achievements were great, and his legacy is assured.”

While comments from world leaders were overwhelmingly positive about Mr. Lee, human rights groups criticized his strong-handed politics.

"Lee Kuan Yew’s tremendous role in Singapore’s economic development is beyond doubt, but it also came at a significant cost for human rights,” said Phil Robertson, the deputy Asia director of Human Rights Watch. "And today’s restricted freedom of expression, self-censorship and stunted multiparty democracy is also a part of his legacy that Singapore now needs to overcome.”