North Korea yesterday reiterated a proposal for unconditional talks with South Korea to ease tensions on the peninsula. The latest offer came days after South Korea dismissed earlier calls by the North for negotiations.

Meanwhile, North Korea's official Twitter account appeared to have been hacked yesterday, believed to be the birthday of leader Kim Jong Il's youngest son and heir-apparent, Kim Jong Un. Four messages critical of the Kims remained posted for 10 hours.

"Let's make a new world by removing our people's sworn enemy – traitor Kim Jong Il and his son Kim Jong Un!" one message read. Another urged the North's military to "point the gun" at Kim Jong Il for diverting money to the country's missile programmes.

Tensions between the two sides escalated after a North Korean artillery barrage on a South Korean-held island near their disputed maritime border killed four South Koreans in November.

"We do not want to see the present South Korean authorities pass the five-year term of their office idly without North-South dialogue," the North's Committee for the Peaceful Reunification of Korea said in a statement. "The South Korean authorities should discard any unnecessary misgiving, open their hearts and positively respond to the North's proposal."

Unification ministry spokesman Chun Hae-sung said South Korea would review the offer, noting North Korea had not sent an official request for talks. North Korea called last week for unconditional and early talks with South Korea, but Seoul dismissed the offer and urged the North to show it has changed through actions, not words.