Douchebaggery, right? Unless he's doing his buddy's bidding - it was Montenegro's Dusko Markovic he pushed out of the way to get to the front of the group, and Putin tried to have Markovic assassinated for joining NATO.
https://www.usatoday.com/story/news/politics/onpolitics/2017/05/25/president-trump-shoved-montenegro-prime-minister-nato/102144808/