South Korea's trade surplus extended its winning streak for the 64th month in a row in May as the country has been basking in brisk outbound shipments on an upturn in global demand, customs data showed Thursday.

The country's trade surplus came to $5.68 billion last month, down sharply from a surplus of $12.9 billion tallied a month earlier, according to the data from the Korea Customs Service.

 Asia's fourth-largest economy has posted the consecutive monthly trade surplus since February 2012.

It logged $6.34 billion in trade surplus with Southeast Asian countries in May, including a surplus with Vietnam worth $2.91 billion, while it recorded an excess of $2.59 billion in trade with China, its largest trading partner.

Trade with the United States recorded a surplus of $864 million, more than halving from $1.78 billion tallied a year ago, amid the Seoul government's efforts to reduce its surplus with the world's largest economy.

South Korea's trade surplus with the United States rose to $23.25 billion in 2016, doubling from $11.64 billion in 2011, a year before the Seoul-Washington free trade pact took effect.

The data showed that South Korea's trade with Middle Eastern nations and Japan recorded deficits of $3.77 billion and $2.17 billion, respectively.

The country's exports have been on a sharp roll since November last year on the back of brisk overseas demand for Korean-made semiconductors and vehicles.

In May, exports jumped 13.3 percent on-year to $45 billion, while imports rose 19.1 percent on-year to $39.3 billion. (Yonhap)