Alec Baldwin unveiled his Donald Trump impression during an appearance on Saturday Night Live.

Baldwin, 58, mocked the Republican nominee's performance in Monday night's first presidential debate on the season premiere of the NBC show.

Kate McKinnon's Hillary Clinton - who came onto the stage coughing and walking with a cane - set up Baldwin's character for one of the biggest laughs of the segment by bringing up Trump's tax returns.

Alec Baldwin unveiled his Donald Trump impression during an appearance on Saturday Night Live

Baldwin, 58, mocked the Republican nominee's performance in Monday night's first presidential debate on the season premiere of the NBC show, alongside Kate McKinnon's Hillary Clinton (right)

'He hasn't released his tax returns, which means he's either not that rich, not that charitable, or he's never paid taxes in his life,' McKinnon said.

Baldwin's Trump retorted, 'wrong, wrong, and warmer.'

Another highlight came in the opening moments, when 'Trump' was drawn into becoming 'unhinged'.

After answering a question about the economy, Trump said: 'I stayed calm, just like I promised. It. Is. Over. Goodnight, Hofstra.'

However, when Lester Holt - played by Michael Che - reminded the Republican nominee the debate had another 88 minutes to go, he lost control.

'My microphone is broken. She broke it. With Obama. She and Obama stole it, they took it to Kenya, they took my microphone to Kenya and now it's broken.'

One of the skit's highlight came in the opening moments, when 'Trump' (pictured) was drawn into becoming 'unhinged'

McKinnon's Hillary Clinton character walked onto the stage coughing and walking with a cane

Veteran journalist Lester Holt, who hosted the debate, was played on SNL by Michael Che (pictured)

Baldwin's Trump then started sniffing loudly, as the real life Republican candidate was mocked for doing during the debate.

Near the end of the opening skit, McKinnon - who won an Emmy last month for her portrayal of the Democratic nominee - broke down in tears as the fictional Trump continued to unravel.

'It's going so well... it's going exactly as I always dreamed,' she said.

She then wrapped up the impression by joking she understands Americans dislike her.

'Listen, America. I get it. You hate me,' Clinton said. 'You hate my voice, and you hate my face.

'Well, here's a tip: If you never want to see my face again, elect me president, and I swear to God I will lock myself in the Oval Office and not come out for four years.

In a Family Feud skit putting Team Clinton up against Team Trump, Larry David revived his role as Senator Bernie Sanders

Ivanka Trump - played by Margot Robbie - appeared in the Feud skit, and Trump's two sons, Don Jr. and Eric, made a surprise appearance by standing up out of nowhere behind her shoulder

The Family Feud skit also featured a cast member playing Bill Clinton, who was on Team Hillary

'But if you don't elect me, I will continue to run for president until the day I die.'

During the last season, SNL cast to select Larry David to play former presidential hopeful Bernie Sanders.

David revived his role on the show for a mock episode of Family Feud, saying Clinton is 'the prune juice of the election' and that if she isn't elected president the US will be 'clogged with a lot of crap for years'.

Other characters included in the game show skit were Ivanka Trump - played by Margot Robbie, a shirtless Vladimir Putin who was on 'Team Trump', Bill Clinton - who flirted with Robbie's Trump at the end of the segment, and Trump's sons, Don Jr. and Eric.

Chris Christie was also skewered in the skit, with the character playing the New Jersey Governor joking about bridges and troubled water.

A shirtless Vladimir Putin was also a member of 'Team Trump' in the SNL Family Feud skit

Another cast member played Chris Christie on the show, and joked the New Jersey Governor's 'Bridgegate' scandal

In real life, Christie is currently dealing with a trial into his 'Bridgegate' scandal.

The network announced Baldwin's deal on Wednesday with a promo on social media, just days before the show began its 42nd season.

It also comes little more than a month before voters choose between Trump and his Democratic opponent, Hillary Clinton.

Trump had previously been played by announcer Darrell Hammond and by the now-departed Taran Killam.

SNL's executive producer Lorne Michaels made the decision to cast the actor over the summer and Baldwin officially signed on earlier this week.

Alec Baldwin's portrayal of Donald Trump was widely celebrated by SNL viewers

Some viewers said Baldwin's Trump impression was 'the best ever', while other said it was 'really funny'

Baldwin, who also starred in Michaels' sitcom 30 Rock, has guest hosted the sketch show a record 16 times since 1990.

He's also a liberal who has been vocal in interviews about his feelings about Trump, who controversially guest hosted an episode of SNL himself last season.

In interviews, Baldwin has called Trump 'the first candidate made of hate' and said he looks like he's been 'dipped in movie popcorn butter.'

Donald Trump himself hosted an episode of SNL himself last season. Above, he is pictured (center) with Taran Killam (left) and Darrell Hammond (right) as Trump

Baldwin's performance was widely praised by viewers, with some calling it 'the best ever'.

'Alec Baldwin is reaching somewhere deep for his Trump impression. It's scary good,' Herb Mitchell said.

'ALEC BALDWIN IS ROCKING TRUMP ON #SNL. Really funny!' Tonja Walker tweeted.