Trump to declare 'emergency' over Mexico border wall

US President Donald Trump is to declare a national emergency to fund his planned border wall with Mexico, the White House has said.

He will sign a border security bill to avert a government shutdown - but also act to bypass Congress and use military funds for the wall, a statement said.

Senior Democrats have responded by accusing him of committing a "gross abuse of power" and a "lawless act".

Building the wall was a key election promise by Mr Trump.

But as president he has so far been unable to get the necessary funding to advance it.

Congress passed the bill - which does not meet Mr Trump's demands for wall funding - on Thursday. It now has to be signed by Mr Trump to become law.

The president insists the US needs a physical barrier on its southern border to stop the flow of migrants, which he says has reached crisis levels.

But critics say the number of migrants at the border is far lower than in previous decades, and that most are trying to enter the US legally.