Israeli Foreign Minister Moshe Dayan conducts secret talks with Egyptian Deputy Prime Minister Hassan Tuhami, he (and other high ranking Egyptians) hold talks with Israeli officials on at least three occasions in 1977 (with help from Moroccan and Romanian intermediaries), which allow the two sides to appraise each others’ intentions and willingness to seriously negotiate. The US is aware that private talks are taking place, but do not have the detail of what is exchanged. (source)