"The reason we chose those seven countries was, those were the seven countries that both the Congress and the Obama administration identified as being the seven countries that were most identifiable with dangerous terrorism taking place in their country," White House Chief of Staff Reince Priebus said.
Trump's controversial executive order, signed on Friday, halted the entire US refugee programme for 120 days, indefinitely banned Syrian refugees, and suspended all nationals from seven Muslim-majority countries -- Iran, Iraq, Libya, Sudan, Yemen, Syria and Somalia.
This is for the first time that the Trump Administration has publicly acknowledged about considering putting Pakistan into that list.
Currently the executive order says that visitors from countries like Pakistan and Afghanistan are subject to "extreme vetting".
More From This Section
Priebus said the executive orders were signed after a lot of planning.
"We're not going to advertise to the world that we're going to put a stop or at least a further vetting on travel in and out of our country from these seven places," Priebus said.
"The President has a call with leadership in Saudi Arabia and the United Arab Emirates and other countries around world. And I'm sure this topic may come up," he said.
Priebus asserted that Americans have to be protected first.
"These are countries that harbour and train terrorists. These are countries that we want to know who is coming and going in and out of to prevent calamities from happening in this country," he said.
"I can't imagine too many people out there watching this right now think it's unreasonable to ask a few more questions from someone traveling in and out of Libya and Yemen before being let loose in the United States. And that's all this is," he said.