Trump tweets that US and Mexico have signed an agreement involving the border and illegal immigration, and he is indefinitely suspending his tariff threat.

Probably because of this news item earlier today:

Mexico sends 6,000 National Guardsmen to control migrants at Guatemalan border
https://www.dw.com/en/mexico-sends-6000-national-guardsmen-to-control-migrants-at-guatemalan-border/a-49096442