Since its independence from Soviet rule in 1991, Baku’s relations with Tehran have never been especially warm – its close ethnic and political ties with Turkey, Iran’s most important rival, almost certainly lie behind that.

Little common ground has been found on the main issues separating the two ex-Soviet states – principally the restoration of blocked transit routes, now the focal point of attempts to move on from the hostilities.

Fitch said that Armenia's 'B+' IDRs reflected strong per-capita income, governance and business environment indicators relative to peers, as well as a robust macroeconomic and fiscal policy framework and credible commitment to reform that were underpinned by an IMF programme.