The president's tweet caused confusion among his followers, who speculated that he was referring to Air Force One.
Some Twitter users also slammed the president for referring to Melania Trump as "it" instead of "she."
The first lady will still be traveling to Philadelphia today.
"It's gonna be the top of the line, the top in the world," Trump said.
In the three-month period between the inauguration and April 2017, the first lady took 21 Air Force jet flights.
The umbrella incident was not the first time Trump has been accused of acting ungentlemanly.
President Donald Trump was not happy when he saw the size of the Kuwaiti ruler's plane.
While not offering details, Muilenburg said the "excellent conversation" with Trump could lead to a deal "in the very near term."