U.S. Republican presidential front-runner Donald Trump said Monday that if elected president, he would try to have wealthy countries like South Korea, Germany and Saudi Arabia shoulder more of the cost for the upkeep of American troops stationed in those countries.

It was the latest in a series of remarks the billionaire real estate mogul has made to accuse South Korea and other nations of relying on the U.S. for their national defense while giving the U.S. nothing in return even as they make a lot of money.

"I'm also going to renegotiate some of our military costs because we protect South Korea. We protect Germany. We protect some of the wealthiest countries in the world, Saudi Arabia. We protect everybody. We protect everybody and we don't get reimbursement,"

Trump said during a news conference to announce campaign pledges on tax reforms.

"We lose on everything. We lose on everything, so we're going to negotiate and renegotiate trade deals, military deals, many other deals that's going to get the cost down for running our country very significantly," he said.

Trump said the trade deals the U.S. has with other countries "are not sustainable" and he would renegotiate them, but did not elaborate. South Korea also has a free trade agreement with the U.S. that has been in effect since 2012.

It was the third time Trump has publicly criticized South Korea over the American troop presence.

In July, he said that whenever South Korea "is in trouble, our military takes care. You know we get nothing." In August, Trump also said that South Korea is making a fortune, but the U.S. sends its troops to defend the Asian ally in exchange for "nothing."

The criticism shows Trump's ignorance about American security interests and policy.

About 28,500 U.S. troops are stationed in South Korea to help defend the Asian ally from the communist North, a legacy of the

1950-53 Korean War that ended in a truce, not a peace treaty, which left the divided peninsula still technically at war.

Seoul has long shared the cost of stationing U.S. forces.

Last year, the two countries renewed their cost-sharing agreement, known as the Special Measures Agreement, with Seoul agreeing to pay 920 billion won ($886 million) for 2014 for the upkeep of the U.S. troops, a 5.8 percent increase from a year earlier.

Moreover, the American military presence on the peninsula is seen as in line with U.S. national interests in a region marked by a rising China.

Trump has emerged as a leading candidate for the Republican presidential nomination for next year's election as he made a series of unbridled remarks on immigration and other sensitive issues that apparently struck a chord with conservatives. (Yonhap)