North Korea has asked Japan if bilateral talks can resume around February even though its provocative rocket launch in December was the cause of their postponement, sources said Sunday.

The government of Prime Minister Shinzo Abe, a nationalist who talks tough on North Korea, is mystified by the proposal, the sources said.

"We're not yet able to figure out what Pyongyang means, and it's still likely the North may repeat provocative acts, such as an additional missile test and a nuclear test," said a senior Tokyo official who spoke on condition of anonymity.