The Oscar-winning actor came out of a closet midway through the sketch to press Eric Trump (played by Alex Moffatt) on the ongoing investigation into the 2016 presidential campaign and the allegations of Russian collusion.
“It’s just me, Robert Mueller, your dad’s friend from work,” De Niro’s Mueller begins.
After De Niro's character jokes with Trump Jr over some misspoken names ("You mean like Mr Pillow Fort", "Manafort"), he finally gets down to why he's there.
"I just wanted you to know, America is going to be just fine. This country is full of good people," De Niro’s Mueller continues.
"Yeah, good people like my Dad," interrupts Moffatt's Trump, to which Mueller replies: "Let's put a pin in that."
The sketch ends with Trump Jr asking whether Mueller was the "worst thing to ever happen to my Dad", to which he responds: "No, getting elected President was the worst thing to ever happen to your Dad." Watch the cold open below.
Jason Momoa, who can be seen in UK cinemas next weekend in Aquaman, hosted the episode, which featured musical guest Mumford and Sons.
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