Top officials in Washington and and Seoul say the sticking point for an agreement continues to be the logistics behind Trump’s demand that South Korea invest $350 billion in the United States.

Korean officials say a direct cash injection could destabilize their economy, and they’d rather do loans and loan guarantees instead. The country would also need a swap line to manage the flow of its currency into the U.S.

The disparity between what Trump is asking for and what South Korea can deliver threatens to overshadow the meeting between Trump and South Korean President Lee Jae Myung in Gyeongju, a historical city playing host to the annual Asia-Pacific Economic Cooperation summit.