Mercer's latest survey shows a weakening US dollar is causing significant changes in rankings of cities in terms of cost of living for expats, with Moscow becoming the most expensive city while Asuncin in Paraguay the least.

     Hong Kong has ranked the sixth, Beijing 20th and Shanghai 24th. Shenzhen ranked 61st while Guangzhou ranked 70th on the list.

     According to the survey, Asian and European cities dominate the top 10. Tokyo climbed two spots to rank as the most expensive city in Asia while London dropped a notch to rank third. Oslo climbed six places to the fourth place, followed by Seoul as the fifth most expensive city.

     Mercer's survey covers 143 cities across six continents and measures the comparative cost of over 200 items in each location, including housing, transport, food, clothing, household goods and entertainment. It is the world's most comprehensive cost of living survey and is used to help multinational companies and governments determine cost of living allowances for their expatriate employees.

     Mercer is a leading global provider of consulting, outsourcing and investment services.

     Yvonne Traber, the principal research manager at Mercer, said: "Our research confirms the global trend in price increases for certain food items and petrol, though the rise is not consistent in all locations. This is partly balanced by