Burundi came out at the bottom of the list Photo:iStock Unreleased

Finland has been revealed as the happiest place in the world, according to a new UN report.

The annual World Happiness Report measures how happy people feel they are and why.

Last year Norway took the number one spot but the country has been knocked from its podium by its Scandinavian neighbour.

Nordic countries usually appear in the top five places but those that are hit with war as well as places in sub-Saharan Africa regularly appear at the bottom.

This year Burundi was declared as the least happy place, replacing the Central African Republic.

The research is carried out by the UN Sustainable Development Solutions Network ranked 156 countries according on things such as social support, healthy life expectancy, social freedom, generosity and absence of corruption.

It also includes information about how happy immigrants are in their host countries - with Finland coming out top in this regard too.

Taking the harsh, dark winters in their stride, Finns said access to nature, safety, childcare, good schools and free healthcare were among the best things about in their country.

World's 10 happiest countries

1. Finland

2. Norway

3. Denmark

4. Iceland

5. Switzerland

6. Netherlands

7. Canada

8. New Zealand

9. Sweden

10. Australia

The United States came in at 18th, down from 14th place last year. Britain was 19th and the United Arab Emirates 20th.

One chapter of the 170-page report is dedicated to emerging health problems such as obesity, depression and the opioid crisis, particularly in the United States where the prevalence of all three has grown faster than in most other countries.

Least Happy Countries

1. Burundi

2. Central African Republic

3. South Sudan

4. Tanzania

5. Yemen

6. Rwanda

7. Syria

8. Liberia

9. Haiti

10. Malawi

While US income per capita has increased markedly over the last half century, happiness has been hit by weakened social support networks, a perceived rise in corruption in government and business and declining confidence in public institutions.

"We obviously have a social crisis in the United States: more inequality, less trust, less confidence in government," the head of the SDSN, Professor Jeffrey Sachs of New York's Columbia University, told Reuters as the report was launched at the Vatican's Pontifical Academy of Sciences.