US President Donald Trump in Washington, January 29, 2017.? [Photo/Agencies]

President Donald Trump, trying to quell a backlash over his "extreme vetting" order, said the United States would resume issuing visas to all countries once secure policies are put in place over the next 90 days.

Under an order he signed on Friday, immigrants from seven Muslim-majority countries were barred from entering the United States. The decision has drawn large protests at many US airports, where some travelers from those countries have been stranded.

"To be clear, this is not a Muslim ban, as the media is falsely reporting," Trump said. "This is not about religion - this is about terror and keeping our country safe. There are over 40 different countries worldwide that are majority Muslim that are not affected by this order.

"We will again be issuing visas to all countries once we are sure we have reviewed and implemented the most secure policies over the next 90 days," he said.