Definition: Financial liability
External debt - IMF
A financial liability (1) requires a debtor to make a payment, or payments, to a creditor in circumstances specified in a contract between them; or (2) specifies between the two parties certain rights or obligations, the nature of which requires them to be treated as financial.
International Monetary Fund (IMF), "External Debt Statistics: Guide for Compilers and Users; Appendix III. Glossary of External Debt Terms", Washington D.C., 2003