Kanye West promised that a new album would arrive on Saturday. Instead, he delivered three songs as the musical guest on “Saturday Night Live” and an impromptu monologue at the end of the show mentioning President Donald J. Trump.

Mr. West, wearing a red Make America Great Again hat, continued his foray into off-the-cuff political commentary after the credits rolled for the season premiere, delivering a scattered speech that was cut off from some broadcasts. In footage from the crowd posted to the comedian Chris Rock’s Instagram account, Mr. West can be seen musing on his support of President Trump and urging, “We need to have a dialogue and not a diatribe.”

Mr. West, who is known for delivering similarly improvised addresses during his concerts, said he is often asked how he can support President Trump because “he’s racist.” “If I was concerned about racism,” Mr. West said, “I would’ve moved out of America a long time ago.” He said Democrats were responsible for a plan to take “fathers out the home and promote welfare.” The rapper also mentioned his long-teased presidential aspirations for 2020 and referred to the “one-sided” liberal nature of the entertainment world as the “S.N.L.” cast stood stoically behind him.