South Park co-creator Trey Parker has made a short, joke apology to President Donald Trump for ridiculing him in the opening show of their 27th season.

The episode, broadcast on Wednesday, depicted the US president naked in bed with recurring character Satan.

Asked about the reaction during a panel at Comic-Con International in San Diego, Parker said, with a mock-serious face: "We're terribly sorry."

The White House has said of the episode: "This show hasn't been relevant for over 20 years and is hanging on by a thread with uninspired ideas in a desperate attempt for attention."

It added: "President Trump has delivered on more promises in just six months than any other president in our country's history - and no fourth-rate show can derail President Trump's hot streak."