The devil is in the details. The 2012 free trade agreement with South Korea led to bigger Korean trade surpluses. That might have been fine if US exports to Korea had increased significantly. But in fact, there was a $6b increase in US exports and a $13b increase in Korean exports, such that the US trade deficit with Korea actually increased(!).
At first it did, but now the deficit with South Korea is in decline. The deficit with South Korea is primarily the result of Hyundai/Kia automobile imports. Both of those brands are suffering severe double-digit sales declines in the U.S. market. As a result the deficit has been dropping for 3 years. During the first 3 months of 2018, the deficit is nearly half what it was for the first 3 months of 2017. The U.S. has surpluses with many nations. The deficit is the result primarily with automobile producing nations. Our deficits with these nations, particularly Germany and Japan, are so large they give us a deficit. Of course the large imports of “stuff” from China also is one of the largest reasons for the deficit.
At first it did but now the deficit with South Korea is in freefall. The deficit has been declining for 3 years and for the first 3 months of 2018, the deficit is nearly half what it was for the first 3 months of 2017. The deficit with South Korea is mostly the result of the imports of Hyundai/Kia automobiles. Both of these brands have suffered severe double-digit declines in the US market. For February 2017 the US deficit with South Korea was nearly $1.3 billion. For February 2018 the deficit was $683 million.