Trump's timekeeping appears to be a topic of conversation throughout this summit.
Footage from last night's reception is also drawing attention on Wednesday morning as it seems to show several foreign leaders discussing the President's lengthy press conferences on Tuesday.
In a 25-second clip, Canadian Prime Minister Justin Trudeau, UK Prime Minister Boris Johnson, French President Emmanuel Macron and Dutch counterpart Mark Rutte appear to share a laugh over Trump's behavior.
Microphones nearby only pick up snippets of the conversations, which starts with Johnson asking Macron why he was late.
Macron's response is inaudible but he can be seen nodding as Trudeau says, "He was late because he takes a ... 40-minute press conference at the top."
While Trump was not mentioned by name, he is the only leader to have held a presser for that length of time, according to CNN's Special Events team covering the summit.
CNN has reached out to representatives for all the leaders who were part of the conversation.
When asked if the leaders were talking about Trump, a spokesperson for Dutch Prime Minister Mark Rutte told CNN on Wednesday they do not comment on closed door sessions. A Elysee Palace spokeswoman declined to comment, adding, "This video does not say anything special.” Meanwhile, a spokesman for Trudeau told CNN they have no comment at this time.
The White House has also declined to comment.
None of the leaders seemed to be aware that the conversation was being recorded, although they were talking openly and loudly enough to be heard by others. The Canadian Broadcasting Corporation first reported on the footage.