Donald Trump signed an executive order to keep migrant families together on Wednesday before addressing supporters at a raucous rally to fiercely defend his hard-line immigration policies.

The US president ruled that families crossing the border will still be arrested and prosecuted, but they will be held together, rather than having the children taken away.

Signing the order, Mr Trump said: "I consider it to be a very important executive order. It's about keeping families together while at the same time being sure that we have a very powerful, very strong border, and border security will be equal if not greater than previously.

"So we're going to have strong, very strong borders, but we're going to keep the families together. I didn't like the sight or the feeling of families being separated."

He also asked the department of defence to assist with sheltering the families, given the current state of overcrowding.