North Korea's exports of mineral resources like anthracite coal and iron ore have lent big support to the country's economy in the past 18 years, with most shipped to China, a report said Wednesday.

Outbound shipments of North Korean minerals totaled $1.35 billion last year, shooting up more than thirtyfold from $430 million in 1998, according to the report released by the state-run Korea Development Institute think tank.

Its total exports tripled to $2.93 billion from $979 million over the same 1998-2015 period.

Moreover, mineral exports accounted for 46.1 percent of the country's total exports in 2015, sharply up from 4.4 percent in 1998.

Some $1.3 billion worth of North Korea's mineral resources were sold in China, the country's strongest ally, last year, taking up 52.4 percent of North Korea-China exports of $2.48 billion.

"North Korea's mineral exports have risen sharply over the past 18 years and become one of the most important sources of hard currency," the KDI report said. "A steep rise in exports of mineral resources has contributed to steady growth of the country's exports amid a series of international sanctions." (Yonhap)