The White House is insisting the Muslim Ban is needed to keep America "ahead of the curve" in tackling terrorism.
There have been widespread protests, against Donald Trump's order, banning people from seven mainly Muslim countries from travelling to the US for 90 days.
In his first statement since leaving office, Former President Barrack Obama says he supports the protesters and that "American values are at stake."
He says he fundamentally disagrees with the notion of discriminating against anyone because of their religion.
But White House press secretary Sean Spicer says President Trump putting America first: