About 2,000 US troops died in the June 1918 Battle of Belleau Wood, fighting a German offensive.
French President Emmanuel Macron and Iranian President Hassan Rouhani spoke by telephone on Sunday and agreed to work together in coming weeks to preserve the 2015 Iran nuclear agreement, the Elysee said in a statement.
The sapling was a gift from Macron on the occasion of his state visit.
Well, after all the brouhaha, it turns out the tree planting was only ceremonial as he plant needed to be quarantined before it could be permanently planted, following U.S. Customs and Border Protection guidelines.
The more mischievous may have even considered the comment to possibly be a tongue-in-cheek reference to Donald Trump's visit to Paris a year ago, when he was caught telling Mr Macron's wife Brigitte that she was "in such great shape", before looking to her husband and saying "Beautiful".
When Trump and Macron planted the tree its roots were safely sealed in plastic.
In 1991, Britain's Queen Elizabeth II helped to plant a little-leaf linden tree on the South Lawn after a storm damaged the one her father, King George VI, had planted in 1937. The photographer reportedly only spotted a yellow spot on the grass where the tree once stood.More news: Trump hails bravery of crew, passengers aboard damaged plane
After entering the First World War in 1917, USA forces were instrumental in beating the Germans back on the Western Front in 1918 and liberating France.
The mystery of the missing oak tree has been solved.
Now the oak sapling is gone - at least temporarily.
But, within days, the tree has mysteriously vanished leaving only a patch of dirt in its place.
In fact, the tree, from Belleau Wood in France where nearly 2,000 American soldiers died in a World War One battle, had been dug up not long after it was planted.
Mr Macron's impassioned speech came after a rally in Nice on Tuesday headed by French far-right leader Marine Le Pen, who joined other anti-immigration counterparts from around Europe in a gathering aimed at energising their campaigns for next year's European Parliament elections.
The White House told NPR the young oak was "moved to a facility" to "ensure the tree's long-term survival" and that it will be replanted as soon as possible. Also puzzling is why the White House didn't announce in advance that the planting last week was a purely symbolic event.