US President Donald Trump signed a national emergency declaration to build his proposed border wall with Mexico, White House Press Secretary Sarah Sanders noted.

White House press secretary Sarah Sanders tweeted a photo of Mr. Trump signing the emergency declaration. The photo was posted during Mr. Trump's Rose Garden announcement, clarifying that the president indeed signed the declaration before the event.

"President Donald Trump signs the Declaration for a National Emergency to address the national security and humanitarian crisis at the Southern Border," Sarah Sanders tweeted.