The U.S. military will send 1,500 additional active-duty troops to the border with Mexico, the White House said on Wednesday, just two days after President Donald Trump signed an executive order on immigration.

President Trump has called migrants, drug-traffickers and smugglers an invasion requiring a military response.

The Pentagon plans to deploy an additional 1,500 troops to the US-Mexico border, in support of the 2,000 National Guard soldiers already there. This decision follows Donald Trump's directive, in which he declared a state of emergency at the border and labeled illegal immigration as an "invasion.

Thousands of additional active duty U.S. troops are being ordered to the southern U.S. border with Mexico. Around 1,500 troops are expected to be part of the first round.