A letter approving the deal was first signed by Lebanese President Michel Aoun in Beirut and then by Israeli Prime Minister Yair Lapid in Jerusalem.
Lapid claimed that Lebanon's signing of the deal amounted to a de-facto recognition of Israel.
In a palace statement after he signed the agreement, Aoun said the deal would have "no political dimensions or impacts that contradict Lebanon's foreign policy."
"The agreement... will take the form of two exchanges of letters, one between Lebanon and the United States, and one between Israel and the United States," said Stephane Dujarric, spokesman for the UN Secretary General.
Lebanon, which has fought a series of wars with Israel, said it would not allow its delegation to be in the same room as the Israeli side, and the two parties would not even sign the same piece of paper.
Rafic Chelala, a spokesman for the Lebanese presidency, confirmed that the Lebanese delegation "will not... meet the Israeli delegation".
This latter article seems to contradict itself - was it one letter signed by both Israel and Lebanon in separate places, or as it two letters between each of them and the US?
I cannot find official copies of the letters from last October to see if both signatures are on the same page. Based on this
Times of Israel article with the text of the letters, it does not appear that Lebanon recognized Israel in any way. But I cannot claim to know much about international treaty law.
Either way, it is fun to see the freak-out.