The Saturday Night Live season finale saw Alec Baldwin's Trump sing Hallelujah and insist he did "nothing wrong" as the threat of impeachment looms large over the White House.

Opening with Baldwin's Trump giving a solemn rendition of Leonard Cohen's 1984 ballad, the screen slowly filled cast members in their respective roles, including White house advisers Kellyanne Conway, played by Kate McKinnon, and Vice President Mike Pence, parodied by Beck Bennett.

The skit plays out amid mounting pressure on the real-life Trump administration, as Russian collusion claims and questions over the firing of former FBI Director James Comey, while leading an investigation into the president, threatens to engulf the Oval Office.

Referencing the snowballing scandals, intensified by numerous leaks apparently aimed at undermining Trump — including the suggestion that he revealed top secret intelligence to Russian diplomats — Baldwin said "I'm not giving up, but I can't speak for any of these people".

Actress Scarlett Johansson, who played Trump's daughter Ivanka earlier in the season, also reprised her role as the president's daughter for the opening, alongside White House Chief Strategist Stephen Bannon as the Grim Reaper.

The opening of the show on Saturday (20 May) resembled Kate McKinnon's delivery of the same song while in character as Hillary Clinton, following the Democratic presidential nominee's election loss in November 2016.

Elsewhere in the episode, host Dwayne Johnson, who made his name as WWE wrestler 'The Rock' in the 90s, added weight to claims he is planning a presidential run.

The 45-year-old, who is now a Hollywood star, jokingly introducing actor Tom Hanks as his 2020 running mate as part of his introductory monologue.

"Starting tonight, I am running for the President of the United States.

"In the past, I never would have considered running for President. I didn't think I was qualified, but now I'm actually worried that I'm too qualified."