If you are planning to visit Luanda, Tokyo, N'Djamena Moscow or Geneva, be warned that they are the top five most expensive cities in the world.

Luanda has pushed Tokyo to second place in this year's survey by Mecer human resource consultants, which covered over 200 cities across five continents.

The survey measures the comparative cost of over 200 items in each location, including housing, transport, food, clothing, household goods and entertainment.

New York is used as the base city for the index against which all cities are compared.

Housing is often the largest expense for expatriates, a factor that plays a big role in the rankings.

Though the report is mainly used by international companies to manage overseas assignment costs for their expatriate workers, it can also help tourists draw up their budgets before travelling.

World centres like Tokyo, Geneva, New York and Hong Kong are often associated with high costs and it is not surprising that they are still viewed as some of the most expensive cities in the world.

But African cities are slowly rising in the annual ranking, with the steeper cost of living mainly driven by scarcity of safe housing for expatriates and tourists, along with inadequate air travel services and the general cost of goods.

Other than Luanda, two other African cities - N'Djamena at number three and Libreville (seven) - made it to the top 10 most expensive cities' roll.

All three are rich in natural resources, enticing oil and mining companies to do business there.

But since they are only starting to develop after years of mismanagement, the cost of living is high.

Air fares are rather steep due to poor access.

Passengers also have to take a connecting flight to get there.

Low bed capacity does not help matters. The scarcity has sent accommodation rates shooting through the roof.

Luanda is now the most expensive in the world and it is only just opening up to international business.

The country's economic prospects and major reconstruction after years of civil war have seen it attract major investors, leading to increased demand for air travel.

The port city, is undergoing major reconstruction sparked by diamond and oil production.

But direct flights to Luanda are few due to strict regulations by the government.

Only recently has it started opening up and signing bilateral agreements that have allowed airlines to fly there.

Carriers like Emirates and British Airways have now increased their flights.

Kenya Airways will start operating in the country from this month after getting clearance from the Angolan government.

KQ is currently running an offer of $50 (Sh4,000) from Nairobi as an introductory price.

An internet search on farecompare.com shows that a flight between London and Luanda costs anything from $1,200 (Sh96,000) with most of them being connection flights through various destinations.

A direct flight on British Airways costs $2,064 (Sh165,120).

Despite these cities being ranked the most expensive in the world, there are cheaper ways to travel and enjoy the sights and sounds at affordable rates.

One can find cheap flights through search engines or travel during the low season.

Booking a ticket way in advance also helps to reduce costs.

Travel agents always have cheaper packages for accommodation and airport transfers.

Talk to your nearest agent to get the best deal or use travel engines like expedia.