From Open Secrets:
Since 2017, no country has spent more money on U.S. influence efforts than South Korea. Governmental and non-governmental entities have spent about $70.5 million in the U.S. Japan ranks second with $51.4 million.
The majority of the spending came from a single organization: the Korea Trade Promotion Center (KTPC), a state-funded nonprofit promoting foreign investment and partnerships, which accounts for $45.9 million of the spending. KTPC also ranks first among registrants.
About $3 out of every $10 spent on foreign lobbying in the U.S. since last year originated from East Asian countries, specifically South Korea, Japan, China, Hong Kong and Taiwan. The five countries have spent a combined $158.2 million since January 2017 — or nearly half of the $374.5 million spent on behalf of the remaining 128 countries in our data.