Can Donald Trump really rename the Gulf of Mexico as the Gulf of America?

We’re going to be changing the name of the Gulf of Mexico to the Gulf of America, said US President Donald Trump in his inaugural speech on Monday. While the casual name-changing attracted laughter from Hilary Clinton and amusement from Mexican President Claudia Sheinbaum, but the question is can Trump really rename it?
“We’re going to be changing the name of the Gulf of Mexico to the Gulf of America, which has a beautiful ring that covers a lot of territory, the Gulf of America,” Trump said. “What a beautiful name. And it’s appropriate. It’s appropriate. And Mexico has to stop allowing millions of people to pour into our country.”
No formal international agreement or protocol governs the naming of maritime areas, nor is there an authoritative global body with the final say on such names. However, the International Hydrographic Organization (IHO) works to standardize maritime names and mediate disputes.
In theory, a directive from the President could change the name of the Gulf in official US documents, but other countries would not be obligated to adopt the change, the Guardian reported.
“He (Trump) says that he will call it the Gulf of America on its continental shelf,” said Mexican President Claudia Sheinbaum. “For us it is still the Gulf of Mexico, and for the entire world it is still the Gulf of Mexico.”
The order mandates that within 30 days, the US secretary of the interior would rename “the US Continental Shelf area bounded on the northeast, north and northwest by the States of Texas, Louisiana, Mississippi, Alabama and Florida and extending to the seaward boundary with Mexico and Cuba.”
The move highlights longstanding naming disputes over key geographic features. For example, Americans refer to the river forming the border between Texas and the Mexican states of Chihuahua, Coahuila, Nuevo León, and Tamaulipas as the Rio Grande, while Mexicans call it the Rio Bravo.
Such naming discrepancies have historically fueled diplomatic tensions between neighboring nations. A notable example is the body of water separating Iran and Saudi Arabia, known as the Persian Gulf by Iran and the Arabian Gulf by Saudi Arabia.