This is not on print media of 12 noon. It looks like Associated Press has someone watching the store and as of now, developing events can be read at this link — although last look it was out of date. It’s being reported on CNN and MSNBC and local radio in San Diego. I can’t locate any official statement from the White House. The reports do not indicate how long this closure will be in effect.
There had been an attempt to negotiate an arrangement to have Mexico retain those seeking asylum, which reports indicate had failed. Here are Trump’s tweets from before the decision was made to close the border.
I post this now, for any reader who knows someone expecting to use this border crossing in the next few hours. The crossing at Tecate, about 50 miles to the East, is not reported as closed.