See these resources:
World Databank which includes World Development Indicators which is provided by the World Bank it includes debt and financial flows for 138 countries.
Global Market Information Database (GMID): GMID includes country economic indicators, trade info, and more. After clicking on Countries, debt is found under Government and Government Finance.
OECD iLibrary: Click on Country Tables under Key Tables. See Statistical Country Profiles for basic numbers including debt and much more.
International Financial Statistics Online: Data covering more than 200 countries and country groupings. Topics include: balance of payments, interest rates, national accounts, prices, production, trade, and population. Updated monthly.
