North Korea said it refuses to give up its nuclear weapons until after the US alters its "hostile policy" toward the North's government and proves it does not pose an atomic threat to the wartime rival. The cryptic statement Tuesday from North Korea's Foreign Ministry is the first to lay out North Korea's nuclear stance since the last round of international talks on disarming the North in December. Analysts say the statement - issued a week before US President-elect Barack Obama's inauguration - also sends a strong signal that Pyongyang is keen to forge diplomatic relations with the next US administration. Stalinist North Korea, one of the world's most isolated countries, has never had diplomatic ties with Washington, which sent troops to back South Korea during the 1950-53 Korean War. Relations warmed under former US president Bill Clinton but went into a deep freeze when US President George W. Bush took office with sharp words for the North.