London: Two fastest emerging economies India and China have weak pension system and need reforms to provide social security to retired citizens, a report by Allianz said on Monday.

Debt-ridden Greece and Asean member Thailand also have weak pension system, according to 'Pension Sustainability Index (PSI)' prepared by Allianz Global Investors.

"... in India and China, the issue is that pension coverage remains extremely low and adequate measures have not been yet implemented to improve this," said Brigitte Miksa, Head of International Pensions at AllianzGI.

The Allianz official further said that Greece, India, China and Thailand show the greatest need for pension reforms. The study charts the relative sustainability of national pension systems in 44 countries.

The report comes at a time when Indian Parliament is in process of passing of a long pending Pension Fund Regulatory and Development Authority (PFRDA). The new pension system also has not yet picked up.

Australia, Sweden, Denmark, New Zealand and the Netherlands top the list of countries in PSI.

Talking about India, the report said the country has extremely low coverage and it remains the primary challenge to policy makers. Only 12 per cent of the population is covered by any type of formal pension arrangement, it said. China and Thailand also score badly.

PSI analyses the current and future prospects of national pension system, looking at variables such as demographic developments, public finances and pension system design.