Comedian Stephen Colbert's profanity-tinged tirade against President Donald Trump, aired nationally on CBS, doesn't merit any action by the Federal Communications Commission, the agency concluded after a review.

After receiving thousands of complaints about the May 1 "Late Show" monologue, which included a joke suggesting a sexual relationship between Trump and Russian President Vladimir Putin, the FCC reviewed the material and decided not to take further steps, the agency said Tuesday in a statement.

Colbert has offered no apology for his remarks, though the late-night host said he should have been less crude. The comedian's biting political humor helped propel "The Late Show" to first place in the ratings for total viewers in the season that just concluded, CBS said in a statement Tuesday.

CBS, in making its pitch to marketers at the annual upfronts in New York last week, featured Colbert prominently in a sizzle reel and song-and-dance routine.

"If you think I love Stephen more now because he's No. 1, you're right," CBS Chief Executive Officer Leslie Moonves said.

CBS has been the most-watched network in the U.S. for 14 out of the last 15 years, with an audience that approaches 10 million viewers a night.

The FCC regulates programming broadcast on television. Programs like "The Late Show" that air after 10 p.m. have looser rules, but they still are prohibited from including obscene content -- overtly sexual, offensive and lacking serious literary, artistic, political or scientific value. It's rare for the FCC to take action against a broadcaster under the rules.