Internally displaced children eat outside their makeshift shelter at a camp outside Mogadishu, Somalia. The country is rated as the world's most corrupt nation. ((Omar Faruk/Reuters))

Somalia and Afghanistan, countries that receive billions of dollars a year in international support, are among the world's most corrupt nations, a watchdog group says.

Transparency International released its annual Corruption Perceptions Index on Tuesday, saying war-ravaged Somalia remains the world's most corrupt country, followed by Afghanistan, Burma, also known as Myanmar, and Sudan.

According to the latest report from the Berlin-based organization, New Zealand is the most principled country, followed by Denmark, Singapore and Sweden.

Canada is tied for eighth place with Australia and Iceland — up one spot from the 2008 survey — while the United States is ranked 19th.

The organization attributed the least corruptible countries' strong performance to their "political stability, long-established conflict of interest regulations and solid, functioning public institutions."

Transparency International's rankings are based on how corrupt a country's government is perceived to be by experts and international institutions like the World Bank and the World Economic Forum.

"The results demonstrate that countries which are perceived as the most corrupt are also those plagued by long-standing conflicts, which have torn their governance infrastructure," the report said.

Transparency International 2009 Corruption Perceptions Index:

 The world's ten most corrupt countries:  The world's ten least corrupt countries:
 Somalia  New Zealand
 Afghanistan  Denmark
 Burma  Singapore
 Sudan  Sweden
 Iraq  Switzerland
 Chad  Finland
 Uzbekistan  Netherlands
 Turkmenistan  Australia, Canada, Iceland
 Iran  Norway
 Haiti  Hong Kong

Source: Transparency International 

with files from The Associated Press