The city of skyscrapers had dropped to second place last year behind Luanda, the capital of Angola.

But it now heads the Asia-dominated list again, according to the 24th annual cost of living survey carried out by advisory firm Mercer.

The survey covers costs ranging from housing and clothes to bread and beer.

It examines the cost of 200 items in each location, including accommodation, transport, clothes, food and entertainment, comparing prices such as a cinema ticket, a pair of jeans, a litre of water, a cup of coffee, a litre of petrol and a litre of milk.

Mercer defines expatriates, also called assignees, as employees of an organisation who are assigned to work in a different country than her or his original country of employment for a definite period of time.

In this year's rankings, Tokyo is the second most expensive city followed by Zurich and Singapore, with Seoul in fifth. This means that four out of five of the world's most expensive cities for expatriates are now in Asia, according to the survey.

The top 10 is completed, in order, by Luanda, Shanghai, N'Djamena, Beijing and Bern.

The world's least expensive city for expats is Tashkent, sitting in 209th place in the Mercer list, below Tunis and Bishkek.

Mercer uses New York as its benchmark for comparing the costs of living in other cities, and measures currency movements against the US dollar.

As a result, the renewed strength of the pound against the dollar resulted in London rising 10 places to 19th on the list.

Also in the UK, Birmingham went up 19 places from last year to 128th and Belfast climbed 18 spots to 152nd. Aberdeen rose by 12 places to 134th.

Western European cities have all risen in the ranking in general owing to currency movements against the dollar as well as inflation. Frankfurt (68th) and Berlin (71st) climbed by 49 places and Munich (57th) rose by 41.

Other cities that rose significantly included Paris (34th), up 28 places from last year, Rome (46th), up 34 spots, Madrid (64th), up by 47 places, and Vienna (39th) up by 39 spots. Moscow (17th), St. Petersburg (49th), and Kiev (173rd) all dropped down the list.