Azerbaijan is proposing to sign a document with Armenia on the basic principles of a future peace treaty as an interim measure as they wrangle over a broader deal, a senior Azerbaijani official said on Sunday. Both Armenia and Azerbaijan have repeatedly said they want to sign a peace treaty to end the conflict over the former breakaway Azerbaijani region of Nagorno-Karabakh. Azerbaijani President Ilham Aliyev said on Saturday a text of a treaty was 80 percent to 90 percent ready but repeated it was impossible to sign it before Armenia amended its constitution to remove an indirect reference to…