On the recordJune 3, 2019
Mexico shouldn't allow millions of people to try to enter our country. And they could stop it very quickly and I think they will. If they won't, we're going to put tariffs on them. And every month, those tariffs go from 5 percent to 10 percent to 15 percent, to 20 and then to 25 percent.
Source
transcripts.cnn.com
