Surplus money registered in the current account balance for the first half of 2016 will be invested into regions that are less developed economically, Bulgaria's Prime Minister Boyko Borisov said on Saturday.

He made the announcement while meeting mayors from three northeastern Bulgarian regions.

He added some projects that are "vital for mayors and the improvement of lives of people" would be funded by the surplus.

Borisov said the northwestern area of the country (which is the EU's poorest region), the so-called "mixed regions" (much of southern and northeastern Bulgaria) and Hemus motorway would be funded as a priority.

The construction of Hemus was marked by scandals related to its tender procedure.

But the motorway is crucial for the development of Bulgaria's north which lags behind the south in terms of economy and infrastructure.