WEST PALM BEACH, Fla. (AP) — A top adviser to President Donald Trump is indicating that Trump is prepared to issue the first veto of his term if Congress votes to disapprove of his declaration of a national emergency along the U.S.-Mexico border.

White House senior adviser Stephen Miller tells "Fox News Sunday" that "the president is going to protect his national emergency declaration." Asked if that meant Trump was ready to veto, Miller said, "He's going to protect his national emergency declaration, guaranteed."

Democrats are planning to introduce a resolution disapproving of the declaration. It is likely to pass Congress, with several Republican senators already indicating they would vote against Trump — though there do not yet appear to be enough votes to override a veto by the president.