A new report from the World Bank says the regulatory climate is improving most quickly in Eastern Europe and Central Asia, where "every country took at least one step to make things easier for business."

For example, Serbia and Montenegro advanced in 8 of the 10 regulatory areas studied, cutting back to 15 days from 51 the time it takes to start a new business.

In the meantime, New Zealand, Singapore and the United States still led the economies where it was easiest to do business. Hong Kong, Japan, Thailand, Malaysia and South Korea were also in the top 30 along with the Baltic states-Lithuania, Estonia and Latvia.

The World Bank said the rise of the Baltic countries was a "remarkable achievement, as only a decade has passed since they first began reforms." Eastern Europe, it said, had done most to reform economies but still has a long way to go.

Difficult challenges remain for many African countries, however, reports the World Bank.

Nonetheless, Rwanda was one nation that showed some progress, ranking among the top 12 countries that took steps to revamp its business climate, streamline customs procedures, and improve credit registration, among other steps.