President Trump on Monday sought to downplay the negative effects of his temporary ban on immigration from seven Muslim-majority countries, and said quick action was needed to stop “bad dudes” from entering the U.S.

After complaints mounted over the weekend that his executive order led to confusion at airports and even among his administration, Trump tweeted Monday to say that just a fraction of travelers were affected, and blamed the clunky implementation of the order on a Delta computer problem, protesters and Senate Minority Leader Chuck Schumer, D-N.Y.