He made the comments during his campaign speech in New Hampshire on Monday.
They came in response to a remark from the audience that it is irrelevant to claim that Seoul pays nothing for the US defending South Korea given that it paid more than $880 million USD last year for the upkeep of US servicemen stationed in the country.
"It's peanuts compared to what it's costing. It's peanuts," Trump said.
He went even further by also pointing the finger at Germany and Japan.
"They are a very wealthy country… We are defending Germany, we are defending Japan, we are defending South Korea, we're defending so many countries, we get peanuts. We get nothing. We get a small payment. It's a fraction, a tiny fraction," he added.
Meanwhile, some South Korean analysts said that Trump's latest remarks show his ignorance concerning geopolitics and US defense policy.
They recalled that in 2014, Washington and Seoul signed a new bilateral cost-sharing deal, known as the Special Measures Agreement.
Under the document, Seoul agreed to pay a whopping $886 million USD for the upkeep of the US troops in 2014, a 5.8 percent increase over 2013.