Setting up and running a business can be stressful at the best of times. But extreme problems or circumstances such as war, endemic corruption or widespread poverty are enough to deter the keenest of entrepreneurs.

CNBC.com takes a look at the world's most difficult countries in which to do business, based on the World Bank's report, "Doing Business 2015". The report ranks 189 countries for ease of doing business, using criteria such as 'getting electricity' and 'getting credit'.

—By Anmar Frangoul, Special to CNBC.com. Published on December 10, 2014.

Devastated by a huge earthquake in January 2010, Haiti is one of the world's poorest countries, with gross national income (GNI) per capita of $810, according to the World Bank. This compares with $53,670 in the U.S., according to the World Bank.

In terms of doing business, the World Bank ranked Haiti ranked third-worst in the world for protecting the interests of minority investors and also rated it poorly in terms of access to credit and ease of registering property.

There are some hopes for improvement however—in 2011, the Inter-American Investment Corporation and the Spanish government established a joint development fund designed to increase the availability of loans and reduce borrowing costs for Haitian small- and-medium-sized companies. This is set to run for 12 years.

A former Portuguese colony, Angola, on the south-east coast of Africa, is one of the continent's biggest producers of oil.

Despite this, it is also one of the poorest countries on the planet, with a GNI of $5,010 and life expectancy of just 51 in 2012, according to the World Bank.

In the Doing Business 2015 report, Angola was rated the third-worst country in the world for enforcing contracts, and also scored poorly for access to credit.

With a GNI of $12,550, Venezuela's income level is described by the World Bank as "upper middle". The socialist country is rich in natural resources including natural gas, gold and diamonds and its crude oil reserves are estimated at around 298 billion barrels.

But the Latin American country ranks poorly in terms of ease of business. It comes second last in the paying taxes category, and scored poorly in the starting a business category.

Afghanistan is suffering the aftereffects of 13 years of bloody and sustained conflict, so security is a massive concern for both business people and citizens.

While the country is ranked a surprisingly high 24th for ease of starting a business, it is rated worst in the world for protecting minority investors. It also scored poorly for cross-border trading and enforcing contracts.

A July 2014 survey by the Afghanistan Chamber of Commerce & Industries found that, "The most important factor for business development is considered to be security; it is followed by lack of market and demand, poor infrastructure, administrative burdens and lack of access to finance."

A huge country blessed with natural resources, the Democratic Republic of Congo (also known as the DRC) has been stricken by years of civil war. According to the United Nations, around 2.7 million people are "internally displaced" in the country, due to ongoing armed conflict in its east.

The DRC remains one of the worst countries in the world to do business, ranking joint worst for resolving insolvency and also scoring poorly for access to electricity and enforcing contracts.

However, it is described by the World Bank as, "among the 10 top improvers worldwide, having improved business regulation the most in the past year among the 189 economies covered."

Buffeted by Libya to the north and Sudan to the east, Chad is one of the world's poorest countries. It had a GNI of $1,020 per capita in 2013, and a life expectancy of 51 in 2012, according to the World Bank.

The country is the fifth worst in the world for launching a business, and the eighth worst for cross-border trading.

However, Chad has improved its record for protecting minority investors, for which it is now ranked joint 146th.

Founded in 2011 after a referendum on independence from Sudan, South Sudan is still unstable. This in part accounts for its low ranking—3rd worst in the world—in the cross-border trading category.

Accessing electricity and registering property are also problematic for entrepreneurs, with South Sudan coming respectively 179th and 180th on these counts.

According to the U.S. Department of State, "Most small South Sudanese businesses operate in the informal economy, where labor laws and regulations are widely ignored."

Since gaining independence from France in 1960, the Central African Republic (CAR) has struggled with dictatorships, coups and conflict in equal measure.

The country's most recent civil war saw thousands die. Its economy shrunk by a vast 36 per cent in 2013, according to the World Bank.

The CAR ranks fourth from bottom in terms of access to electricity and third from bottom for ease of starting a business.

Three years after the overthrow and death of Colonel Muammar Gaddafi, oil and gas-rich Libya is still struggling for stability.

The country ranked joint-last for handling construction permits, joint-last for registering property and second-last for protecting minority investors.

Rival militia are still engaged in fierce fighting in Libya and this summer the security situation deteriorated further. The United Nations says that over 100,000 Libyans are displaced as a result of the current fighting.

With a GNI of just $490 per capita, Eritrea is described by the World Bank as, "one of the least developed countries in the world." Roughly two-thirds of Eritreans live in rural areas.

The country—which has been criticized for its alleged extrajudicial killings and torture and lack of openness—came joint last for dealing with construction permits, joint last for access to credit, and 176th for registering property.