Wow; a simple question with such passionate answers! Cool your jets people - please don't post unless you've got a proper, historical answer which goes in-depth and seeks to answer the question.
We mods have done a looooooooooooot of deleting in here and it would be nice if we could avoid more, yes?
De Gaulle didn't respond, although neither Rusk nor Johnson really expected a response. Rather, they wanted to highlight the past sacrifice of Americans on behalf of France and that NATO still provided security for the French regardless of whether they contributed to it militarily or not.
De Gaulle pulled France out of the military side of NATO for domestic reasons knowing that it would have no bearing on France's security. It is important to remember that he came to power again as France was losing its last major colony in Algeria, which sparked concerns among the population that France was no longer a great power. By pulling out of NATO he asserted that France was not a subservient power, but rather a key player in its own right on the global stage. This played well at home, even though it was largely irrelevant globally. He spent the rest of his time in power trying to chart a middle way, along with other figures like the mayor of West Berlin Willy Brandt.
De Gaulles efforts proved fruitless, and he was unable to effectively respond to a changing domestic environment, nearly losing power in 1968 and then resigning in 1969.
Also, it's worth to be noted that all of WWII cemeteries land in France were given to the country which soldiers are buried in.
Please however note that while the USA are the owner of, for example, the Normandy American Cemetery and Memorial, these terriotries are not falling under extraterritoriality, and despite the American flag flying there, French law still applies. (Example of extraterritoriality include the UN HQ or a lot of Vatican city assets. Ambassy aren't, they are just granted diplomatic immunity.)