Outgoing Czech Prime Minister Mirek Topolanek, whose country presides over the European Union until June 30, today called North Korea's nuclear programme "extremely dangerous.", according to dpa. Topolanek spoke to reporters after bilateral talks with his Japanese counterpart Taro Aso, who arrived in Prague for an EU summit on Monday to be chaired by Czech President Vaclav Klaus. On Wednesday, North Korea threatened to test a nuclear device and test ballistic missiles unless the United Nations Security Council apologized for slamming Pyongyang's April 5 rocket launch. The United States urged North Korea to stop issuing threats and return to negotiations. While the Stalinist state insisted it had launched a communications satellite, Western powers viewed it as a covert long- range ballistic missile test. North Korea said it will restart its nuclear programme for self- defence after pulling out of the six-nation talks that produced a North Korean agreement in 2007 to denuclearize in return for aid and improving diplomatic relations.