Biden explicitly ruled out sending US troops on the ground. That's not a Trump-driven position.

Now, that phrase may be important -- there may have been F-35s that have flown through the area, as we know that there have been a lot of air tankers flying ovals by the border refueling something, and a photo from a tanker of an F-35s in stealth configuration being refueled was geolocated to Poland, just across the border. But if so, they aren't shooting, just using sensors to gather information.