The Seoul-based Bank of Korea said in a statement that North Korea's economy shrank 4.1% last year from a year earlier. The statement said it was the North's second straight year of contraction and the worst performance since 1997, when the economy was estimated to have shrunk 6.5%. In the mid-1990s, North Korea suffered a crippling famine that was estimated to have killed hundreds of thousands of people.
North Korea doesn't publicly release data on its economy. The Bank of Korea said its estimates are based on information provided by various South Korean government agencies, including the Unification Ministry and the Korea Trade-Investment Promotion Agency.
U.N. sanctions on North Korea were toughened after North Korea conducted high-profile nuclear and missile tests in recent years. Experts say bad weather conditions like a prolonged drought and a heat wave last year have devastated the North's farm sector.