South Korea aims to issue state bonds worth about 6 trillion won (US$5.4 billion) in April, the finance ministry said Thursday.According to the ministry, the government seeks to sell 1.4 trillion won in three-year Treasuries, 1.55 trillion won in five-year debts and 1.8 trillion won worth of 10-year bonds next month.It also plans to issue 600 billion won worth of bonds that mature in 20 years and 650 billion won in 30-year bonds.The ministry said it sold about 6.82 trillion won worth of bonds this month.