Democratic presidential candidate Joe Biden has raised concern after he delivered a confused campaign speech in South Carolina, saying he was a “candidate for the United States Senate” and that people could “vote for the other Biden” if they did not like him.

His speech at the First in the South Dinner on Monday came ahead of the presidential primary in the state on Saturday.

A video of Mr Biden’s speech shared widely on social media showed him saying: “My name is Joe Biden. I’m a Democratic candidate for the United States Senate. Look me over, if you like what you see, help out. If not, vote for the other Biden.”

Mr Biden, 77, has made a series of confusing and controversial statements during a presidential campaign to date that has seen his poll ratings tumble.

Earlier this month, he mistakenly referred to New Hampshire as Nevada on the night of the state’s first-in-the-nation primary.

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The speech led some on social media to raise concerns about his health and how rigorous campaigning was affecting him.

Despite the gaffe, Mr Biden has a lead over Senator Bernie Sanders in the latest South Carolina poll of Democratic voters, with both candidates ahead of the pack.