The presidential office stressed that negotiations with the United States are proceeding with South Korea's national interest as the top priority following U.S. President Donald Trump’s claim that Seoul’s pledged 350 billion U.S. dollar investment must be paid “up front.”

At a briefing on Friday, presidential spokesperson Kang Yu-jung said that it would be inappropriate for the top office to evaluate the remarks of a foreign head of state and added that it is too early to comment on the substance and nature of the investment package.

Kang also addressed foreign media reports that quoted U.S. Commerce Secretary Howard Lutnick as suggesting South Korea should increase the size of its U.S. investment. She reiterated that Seoul is negotiating with the national interest foremost in mind and declined to elaborate further.

This comes after Donald Trump on Thursday reaffirmed that he expects to receive South Korea’s pledged 350 billion dollar investment "up front."

Seoul agreed in July to provide the investment package in exchange for lower U.S. tariffs on South Korean imports, but the two sides have yet to agree on how the package will be structured and implemented. 

South Korea has requested a currency swap agreement with Washington and warned that an immediate lump-sum payment could expose it to significant foreign exchange risk.