NATO summits are a big deal for all leaders taking part, but as usual Donald Trump wants to make sure he is in the spotlight.
Before speaking at the Nato headquarters in Brussels, the US President was filmed shoving past another fellow leader to be at the front of the pack.
Footage shows the moment Trump slaps his hand on the arm of Prime Minister of Montenegro Duško Marković before shoving him out of the way.
The PM seems startled at first to see the president barging his way to the front of the group, which included the likes of Angela Merkel, Emmanuel Macron and Theresa May.
Markovic was mid-conversation with the Lithuanian President Dalia Grybauskaitė when the surprise guest pushed past.
Trump later gave a speech at in front of the other leaders, criticising those who didn't pay their way when it came to NATO contributions.
Merkel also unveiled a slab of the former Berlin Wall to act as a permanent reminder of the divisions that once hit Europe.