With all due respect, the only previous "negotiations" DeGaulle ever had with Viet Nam was a French surrender in 1954.
Viet Nam was JFK's war so I wouldn't think his Brother would turn 180 degrees for a fast exit.
That was a long time ago and politicians have been known to do/say anything to get elected.
I do recall, at JFK's funeral, General Degaulle was offered a ride in the procession to Arlington, but said that since Mrs. Kennedy was walking, he would also walk. That was a very respectful, statesman like response to a nation in mourning.