Director of National Policy Kim Yong-beom said “substantial” progress had been made during recent follow-up trade negotiations with the United States.

Speaking to reporters at Incheon International Airport upon his return from the U.S. on Sunday, Kim said the talks had taken place in a “serious and constructive” atmosphere.

The remarks came as South Korea and the United States continue negotiating the structure of Seoul's pledge to invest 350 billion U.S. dollars in its ally's economy in exchange for lower tariffs. U.S. President Donald Trump has stated multiple times that the funds should be delivered "up front," but Seoul has vowed not to accept such an arrangement without a currency swap facility to mitigate shocks to its economy.

Kim said the chances of concluding the negotiations in time for the Asia-Pacific Economic Cooperation summit in Gyeongju have improved since his U.S. trip.

He said the two sides had reached significant agreement on most issues but that “one or two” matters still require further discussions.

Kim added that these matters will be thoroughly reviewed with relevant ministries, after which South Korea will convey its revised stance and hold additional talks.

Kim declined to provide details regarding Seoul’s pledge to invest 350 billion U.S. dollars in its ally's economy but said both sides agree that any investment framework must be mutually beneficial and within South Korea's financial capacity.