On 26 July 1914, the Austro-Hungarian Minister of Foreign Affairs, Leopold Count Berchtold (pictured), sent a private telegram to the Austro-Hungarian Ambassador to Russia, Frigyes Count Szapary. In his telegram, Berchtold clarifies his position on the Austro-Hungarian ultimatum to Serbia.
Count Berchtold to Count Szapary. Vienna, 26 July 1914.
I request that Your Excellency to find opportunity to speak to Herr Sazonov on the matter of the cyphered memoir of 25 July, which arrives in Petersburg tomorrow morning.
As to the question of a prolongation of the term of the ultimatum, which, as you know from my telegram of yesterday, Prince Kudacheff [i.e. Russian Chargé d’Affaires (the defacto Ambassador) to Austria-Hungary] proposed here, my telegram of 24 July gives you all the necessary information.
Source: 1919 Austro-Hungarian Red Book, with minor edits.