"This monument will never be desecrated, these heroes will never be defaced," Trump said as he began the speech.
Native American protesters were arrested after blocking a road to the South Dakota landmark, according to video livestreamed on social media. They have criticized Trump's visit for increasing the risk of spreading the COVID-19 virus and for celebrating U.S. independence in an area that is sacred to them.
Trump will view a fireworks display as part of July 4 celebrations at the monument, which depicts the images of U.S. presidents George Washington, Thomas Jefferson, Theodore Roosevelt and Abraham Lincoln.
A Trump campaign official said the president, who has criticized protesters for tearing down statues during demonstrations against racial inequality, would criticize people who are trying to "tear down" the United States.
The president has come under criticism for his reaction to nationwide protests sparked by the death of George Floyd, a Black man who died in police custody in Minneapolis. Trump has emphasized a "law and order" response to the demonstrations.
DONALD TRUMP: There could be no better place to celebrate America's independence than beneath this magnificent, incredible, majestic mountain monument to the greatest Americans who have ever lived. Today we pay tribute to the exceptional lives and extraordinary legacies of George Washington, Thomas Jefferson, Abraham Lincoln, and Teddy Roosevelt.
I am here as your president to proclaim before the country and before the world, this monument will never be desecrated.
These heroes will never be defaced. Their legacy will never, ever be destroyed. Their achievements will never be forgotten. And Mount Rushmore will stand forever as an eternal tribute to our forefathers and to our freedom.