Defense Department officials said they were required by Congress to make a plan to use, transfer, or donate unused border wall.

U.S. officials can withhold their rationale in family separation cases that relate to national security. There have been about 80 children separated for these reasons this year, with an estimated 50 of them Russian.

Canada's government on Monday proposed C$1.3 billion ($913.05 million) for border security after U.S. President-elect Donald Trump threatened tariffs unless Canada reduced the movement of migrants and drugs into the United States.

Canada has made its border increasingly secure. But enforcement is difficult on the world’s longest land border, and President-elect Donald Trump’s immigration rhetoric pressured Canada to invest in security or face tariffs.

Canada battles to stop border crossings as Trump threat looms | REUTERS Canada is struggling to control US-bound migrant crossings across the world's longest land border. Despite installing new technology to try stop the flow,