In a move likely to have implications for Japan, U.S. President Donald Trump claimed Wednesday that discussions have begun with South Korea to get the Asian ally to pay more for the cost of maintaining U.S. troops there.

"South Korea has agreed to pay substantially more money to the United States in order to defend itself from North Korea," Trump wrote in a Twitter post, saying that Seoul had paid the U.S. "very little" over the "past many decades."

"Talks have begun to further increase payments to the United States," he wrote. "South Korea is a very wealthy nation that now feels an obligation to contribute to the military defense provided by the United States of America."