Russia argues that Turkish-Armenian relations should not be linked to Nagorno-Karabakh, a view shared in Washington.

So Turkey did another volte-face. Mr Erdogan declared that friendship with Armenia was no longer possible unless it withdrew from Nagorno-Karabakh.

The American Secretary of State Hillary Clinton has told Azerbaijan that the United States is ready to help it reach a deal with Armenia over the disputed enclave of Nagorno-Karabakh.