EU Enlargement: government debt as a percentage of GDP for candidates 2000-2021

As of 2021, Montenegro had the highest government debt of any candidate country for membership of the European Union, with its debt being worth approximately 86 percent of its gross domestic product. This debt burden was in fact below the average government debt level of European Union countries, which stood at 87.9 percent in the same year, driven by highly indebted countries such as Greece, Italy, and Portugal. 

All candidate countries for EU membership apart from Montenegro have relatively low levels of government debt, a positive sign for their chances of joining the EU, as the Copenhagen Criteria require that a country which joins the EU must have a stable market economy which will be able to deal with the impact of joining the union. Government debt levels of around 50 percent are common among developed countries and are not considered to be detrimental to economic progress.