NEW YORK (CNNMoney.com) -- If your boss wants to transfer you to Moscow this year, he'd better offer you a fair sum to do so - or even a downright handsome one depending on where you live now. That's because Moscow has just been designated the world's most expensive city for the second year in a row by Mercer Human Resource Consulting.

Using the cost of living in New York as a base, Mercer determined Moscow is 34.4 percent more expensive after taking into account the cost of housing, transportation, food, clothing, household goods and entertainment.

Moscow tops the list as the most expensive city for the second year in a row. World's most expensive cities 2007 1. Moscow 2. London 3. Seoul 4. Tokyo 5. Hong Kong 6. Copenhagen 7. Geneva 8. Osaka 9. Zurich 10. Oslo 11. Milan 12. St. Petersburg (Russia) 13. Paris 14. Singapore 15. New York City 16. Dublin 17. Tel Aviv 18. Rome 19. Vienna 20. Beijing Source:Mercer

"The appreciation of the ruble against the U.S. dollar, combined with ever-increasing accommodation charges, has driven up costs for expatriates in Moscow," Mercer research manager Nathalie Constantin-Metral said in a statement.

A luxury two-bedroom in Moscow now rents for $4,000 a month; a CD costs $24.83, and an international newspaper, $6.30, according to Mercer. By comparison, a fast food meal with a burger is a steal at $4.80.

London takes the No. 2 spot, up from No. 5 a year ago, thanks to higher rents and a stronger British pound relative to the dollar. Mercer estimates London is 26 percent more expensive than Gotham these days.

Following closely on London's heels are Seoul and Tokyo -- Nos. 3 and 4, respectively -- both of which are 22 percent more expensive than New York, while No. 5 Hong Kong is 19 percent more costly.

On the opposite end of the spectrum, Asuncion in Paraguay is ranked as the world's least expensive city for the fifth year running. Mercer estimates that to live in Asuncion costs half as much as it does to live in New York.

Among North American cities, New York and Los Angeles are the most expensive and are the only two to rank in the top 50 of the world's most expensive cities. But both have fallen in their rankings since last year's survey -- New York came in 15th, down from 10th place, while Los Angeles fell to 42nd from 29th place a year ago. San Francisco came in a distant third at No. 54, down 20 places from a year earlier.

Toronto, meanwhile, ranks as Canada's most expensive city but fell 35 places to take 82nd place worldwide.

In Latin America, Sao Paulo and Rio de Janeiro are still the most expensive cities, coming in at Nos. 62 and 64 worldwide. In Australia, Sydney is the priciest place to live and ranks No. 21 worldwide. In the Middle East, Tel Aviv takes the cake, coming in at No. 17 globally, while in Africa, Accra in Ghana will cost you the most. It ranks No. 76 worldwide.