Temporary flight restrictions for VIP movement have been imposed around Brownsville, Texas, during the launch window, which opens at 4:00 pm (2200 GMT). Meanwhile, the usual air traffic restrictions over Trump's West Palm Beach residence will be lifted at the same time.
US media outlets have reported on Trump's plans to attend, with NewsNation quoting the office of local House Representative Vicente Gonzalez.
SpaceX owner Musk, the world's richest man, has been a near-constant presence at Trump's Mar-a-Lago estate since the Republican's election victory earlier this month.
He is set to co-lead a new government efficiency department, raising concerns about potential conflicts of interest given SpaceX's extensive contracts with NASA and the Department of Defense.
Tuesday's launch will mark the fastest turnaround between test flights for the world's most powerful rocket -- a gleaming stainless steel colossus central to Musk's vision of colonizing Mars and making humanity a multiplanetary species.
It comes just over a month after SpaceX pulled off a stunning technical feat, successfully catching Starship's massive booster stage with the "chopstick" arms of its towering launch structure, underscoring its position as the world leader in reusable rocketry.
Trump was effusive in his praise for Starship during his election night victory speech, calling the booster catch "a beautiful thing to see" while emphasizing that the United States alone was capable of such a technological triumph.
