WASHINGTON - President Donald Trump could issue additional executive orders to include "Pakistan and others" to the list of Muslim-majority countries whose people are banned from emigrating to the United States, White House Chief of Staff Reince Priebus said Sunday.

"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," Priebus, told CBS News.

"Now, you can point to other countries that have similar problems, like Pakistan and others. Perhaps we need to take it further. But for now, immediate steps, pulling the Band-Aid off, is to do further vetting for people travelling in and out of those countries," Priebus said in response to a question.

Under the present executive order, visitors from countries like Pakistan, Afghanistan and Saudi Arabia are subject to extreme vetting.

“Perhaps other countries needed to be added to an executive order going forward,” Priebus said regarding expansion of Trump’s immigration action.

“This is all done for the protection of Americans,” Priebus said. President Trump is not willing to get this wrong.”

Priebus also suggested that US citizens travelling to any of the seven countries outlined in the executive order could be subjected to additional vetting by Transportation Security Administration officers upon re-entry to the United States.

“I would suspect that if you’re an American citizen travelling back and forth to Libya, you’re likely to be subjected to further questioning when you come into an airport,” he said. “I would suspect that most Americans would agree that that might be a good thing to do.”

Meanwhile, Priebus said Trump's executive order does not affect green card holders. In an interview on NBC's "Meet the Press," Priebus said "We didn't overrule the Department of Homeland Security, as far as green card holders moving forward, it doesn't affect them."