Trump vetoes lawmakers' measure against border wall, Attorney General Bill Barr Supports Trump's Declaration of National Emergency

WASHINGTON (Reuters) - President Donald Trump on Friday vetoed a measure to terminate his emergency declaration over a border wall, striking back at Republican and Democratic lawmakers who opposed the controversial move with the first veto of his presidency. 

Before issuing the veto, Trump again said there was a tremendous national emergency, while U.S. Attorney General William Barr said the action the president had taken was legal. 

The emergency declaration is being challenged in court as an unconstitutional usurpation of Congress' power of the purse. 

Trump was flanked by border officials and people who have had family members killed by someone who was in the United States illegally as he issued the veto during an Oval Office signing ceremony.