The best places to live after retirement are mainly located in Europe with Norway, Switzerland and Iceland the top countries to offer a comfortable environment for those who hung up their boots, a recent report has shown.

The Global Retirement Index (GRI), now in its fifth year, measures standards of living of retirees in 43 countries worldwide. The list computes a retirement security score by analyzing 18 points relevant to retiree welfare across four categories, namely finance, healthcare, material well-being and quality of life.

The index is published by French asset management company Natixis Global Asset Management.

According to this year's ranking, Sweden ranked third, followed by New Zealand, Australia, Germany, and Denmark. The Netherlands took the ninth position and Luxembourg was the last of the top 10 countries that provide retirement security.

Despite remaining among the 25 countries with the highest overall scores, the US and Austria showed dramatic declines in 2017.

US slipped three ranks to No. 17 but recording the sixth-lowest score for income equality -- a factor which, along with income per capita and unemployment rate, constitutes the score to gauge the "material well-being" category. This measure sizes to which extent a population can supply its material needs.

According to Bloomberg, the sharp drop of the US results from a large income equality gap and too few workers to support its growing population of retirees.

The report pointed out that although BRICS countries fell to the bottom of the list, they showed great potential to offer a comfortable retirement for their citizens as they enjoy a relatively low tax burden and unemployment rate.

Such environment sets the foundation to improve retirement security programs in the future. China came in at 38, ahead of Russia (40), Brazil (41) and India, which was ranked last.

South Africa was not among the 43 countries surveyed.

The report noted that the number of people over the age of 65 has already reached 600 million worldwide. According to data from the World Bank, the world's aging population will triple in 2050 to 2.1 billion people. How to solve pressure on society brought about by an increasing population of retirees and longer lifespans should be the main challenge that each country will have to face in the next 30 years.

Although outshining other countries, European nations did not do well in public pension systems, as they generally have high tax rates, increased liabilities and funding shortfall. However, the quality of life and material well-being can offset such disadvantages, as observed in the cases of Germany, Denmark and Sweden.