Mr Trump has not hid his disdain for NATO, which he has called “obsolete” because it is not addressing “taking care of terror.”
In an address to other NATO leaders he lectured them on needing to pay their “fair share” in the alliance.
The press pool reports that Mr Trump and the other NATO leaders subsequently “ignored one another during ‘family photo’ op in Brussels.”
The shove is likely to become another viral moment from Mr Trump’s first overseas trip as president. Earlier in the trip First Lady Melania Trump can be seen swotting away his attempts to hold her hand.