Image copyright AFP Image caption Norway is the best country for older people, followed by neighbouring Sweden

Norway is the best place to grow old, according to an index of the quality of later life in 96 countries.

HelpAge International's Global AgeWatch Index measures the social and economic welfare of those over 60.

Published on the UN International Day of Older Persons, it ranks Australia, Western Europe and North America highly, and Afghanistan last.

The report predicts that by 2050, 21% of the global population will be over 60.

The index measures four areas - income security, health, personal capability and whether the person lives in an "enabling environment".

Hot on the heels of Norway comes Sweden, closely followed by Switzerland, Canada and Germany.

The report says that by 2050, some 40 countries in the index will have populations where 30% are aged 60 or over.

The UN has said that the number of those aged 60 or over is expected to reach 1.4 billion by 2030.

Image copyright AFP Image caption Mexico has shot up the index for its commitment to income security for older people

Analysis: Mike Wooldridge, world affairs correspondent

Experts point out that the increasing numbers of people surviving into older age are, of course, a cause for celebration - advances in healthcare and in nutrition, better sanitation, and more economic prosperity are all contributory factors.

Add in other factors like falling birth rates and it is clear why we see not just more people living longer, but countries with higher percentages of older people as well.

But the question is whether this can be turned into more positive ageing for those who have little or no social protection or savings - an acute challenge for many in the developing world.

It is made worse where the tradition of caring for the elderly within extended families is weakening.

There is change taking place. The growth of tax-financed, non-contributory "social pensions" is seen as key to helping to tackle inequality for the older age group.

A slogan often heard in global development is "leave no-one behind" - the welfare of those in later life is as much of a test of it as the young.

Several Latin American countries - particularly Mexico and Peru - have leapt up the index for their commitment in ensuring "social pensions" for the poorest older people.

These are tax-financed, non-contributory pensions that ensure a basic income for the most vulnerable.

In Mexico, nearly nine out of every 10 people aged 65 and over receive a social pension.

Because of this, Mexico ranks at 30 on the index, outstripping the BRICS nations - Brazil, Russia, India, China and South Africa.

Peru has implemented the Pension 65 programme, which provides older people with 250 nuevo soles (£53) every two months.