NEW YORK • Norway has displaced Denmark as the world's happiest country in a new report that calls on nations to build social trust and equality to improve the well-being of their citizens.

Norway's Nordic neighbour Iceland as well as Switzerland round up the top four, according to the World Happiness Report 2017 produced by the Sustainable Development Solutions Network (SDSN), a global initiative launched by the United Nations in 2012.

"All of the top four countries rank highly on all the main factors found to support happiness: caring, freedom, generosity, honesty, health, income and good governance," the summary explains.

Countries in sub-Saharan Africa, along with Syria and Yemen, are the least happy of the 155 nations ranked in the fifth annual report released yesterday.

Singapore is ranked 26th - the highest among Asian countries but four rungs lower than last year.

"Happy countries are the ones that have a healthy balance of prosperity, as conventionally measured, and social capital, meaning a high degree of trust in a society, low inequality and confidence in government," Professor Jeffrey Sachs, director of the SDSN and a special adviser to the UN Secretary-General, said in an interview.

The aim of the report, he added, is to provide another tool for governments, business and civil society to help their countries find a better way to well-being.

The rankings are based on six factors - per capita gross domestic product, healthy life expectancy, freedom, generosity, social support and absence of corruption in government or business.

Among the wealthier countries, the differences in happiness levels had a lot to do with not money but "differences in mental health, physical health and personal relationships: the biggest single source of misery is mental illness", according to the report. "Income differences matter more in poorer countries, but even their mental illness is a major source of misery," it added.

Another major country, China, has made major economic strides in recent years. But its people are not happier than 25 years ago, it found. The country is ranked 79th.

The United States slips to No. 14, due to less social support and greater corruption. Economic measures that the administration of President Donald Trump is trying to pursue will make things worse, said Prof Sachs.

"They are all aimed at increasing inequality - tax cuts at the top, throwing people off the healthcare rolls, cutting Meals on Wheels in order to raise military spending. I think everything that has been proposed goes in the wrong direction," he explained.

Norwegian Premier Erna Solberg welcomed the report as "a nice validation on a Monday morning. For many years, Norway has been behind Denmark in this ranking".

"I've made a point of it in many dinner speeches in the Nordics. Now I must find something new!" she said in a message on Facebook.

In Asia, Singapore is followed by Thailand (32), Taiwan (33), Malaysia (42), Japan (51), South Korea (56) and Hong Kong (71), among others. Surprisingly Bhutan, the Himalayan country known for putting an emphasis on its citizens' well-being rather than economic development, is placed a dismal 97th in this latest ranking, down from 84th last year.

But comparing happiness levels between the period 2005-2007 and 2014-2016, Singapore comes in at a lowly 80th - out of 126 countries - due to a slight dip in its score.

Prof Sachs would like nations to follow the United Arab Emirates and other countries that have appointed ministers of happiness.

"I want governments to measure this, discuss it, analyse it and understand when they have been off on the wrong direction," he said.

REUTERS, AGENCE FRANCE-PRESSE