(CNN) In a press gaggle before heading off to California to boast of his new-but-not-new wall on Friday President Donald Trump said that Mexico had recently increased its apprehension of migrants in response to his threat of shutting down the US southern border.

"Mexico has been absolutely terrific in the past four days." Trump said. "They're apprehending everybody. Yesterday they apprehended 1,400 people. The day before it was a thousand. And if they apprehend people at their southern border, that's a big home run."

Facts first: While CNN could not verify Trump's claims of the last two days, the apprehension rate in Mexico did see a recent increase over the first two days of April. It's unclear whether that increase is a result of more migrants coming through Mexico, or of the Mexican government stepping up its efforts.

During an April 4 radio interview , Tonatiuh Guillén, commissioner of Mexico's National Migration Institute, said that during the first two days of April, Mexican immigration agents apprehended 1,259 undocumented immigrants. If that number were to stay consistent throughout the month, apprehensions would hit 18,885 during April.

Mexican authorities apprehended 12,746 migrants during the whole month of March, Guillén said. That's up from 9,894 apprehensions in February, according to Guillén, and about 7,500 in January.

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