He characterized such efforts as "a movement of the people … against the elite."
In a video on Trump Jr.'s social media accounts, headlined "here's what comes next for our amazing movement," he told supporters, "Just want to make sure everyone knows, guys, we are not done yet."
Trump Jr. then shared a recent video clip that showed his father walking off the golf course while saying, "We haven't finished yet."
"He's actually accurate," Trump Jr. said of his father's remarks.
"The reality is this movement isn't over. All of the blood, sweat, and tears that you guys have all put into this thing is very much still alive and well. You see that. I mean, this is really a movement of the people, a movement against the establishment, a movement against the elite."
"A lot of those things have been brewing for quite some time. And that's why for me I'm still standing engaged and we're going to get in there and fight to elect people who really represent the people—people like you who have gone through so much."
Trump Jr. said that the former president is still "going to be in that fight."
"I know he's still going to keep going. I know we're up against a lot, we always have been," Trump Jr. said, later adding that is father is "going to be in there making sure that we have people who truly represent what America is all about."