MOON TOWNSHIP: It's barely 2018, but US President Donald Trump is gearing up for a 2020 re-election campaign, with a familiar sounding new slogan: "Keep America Great!", reports AFP.

Addressing a rally in a Pittsburgh suburb, Trump endorsed a Republican candidate in a closely-watched upcoming special congressional election, before turning to his own political future.

"Our new slogan when we start running -- can you believe it, in two years from now -- is going to be: 'Keep America great, exclamation point,'" he said. "Keep America great!"

Trump's snappy but controversial "Make America Great Again" slogan dominated the 2016 election atmosphere, and his supporters -- many of whom wore red hats bearing the phrase at the rally -- have used it as a catchphrase for the president's first year in office.