Trade negotiations between the United States and South Korea have gotten more complicated with the possibility of increasing Seoul's 350 billion U.S. dollar investment pledge now on the table.

The Wall Street Journal reported Thursday that U.S. President Donald Trump is attempting to slightly modify the trade agreement Washington and Seoul reached in July.

The report states that U.S. Secretary of Commerce Howard Lutnick, who is leading the trade negotiations, recently discussed with South Korean government officials the possibility of slightly raising the amount of Seoul's original pledged investment of  350 billion dollars.

Sources say that the final amount could move closer to Japan’s 550 billion dollar investment in the U.S.

According to the report, Lutnick emphasized to South Korean officials that the U.S. government prefers the investment in the form of cash, rather than loans.