North Korea may be preparing to launch a long-range missile within a week, Japan's Kyodo news agency has reported, citing an unnamed Japanese government official.
The official cited signs of possible preparations for a missile launch based on analysis of satellite imagery of the North's Tongchang-ri missile test site on its west coast.
The report comes amid discussions among UN Security Council members for fresh sanctions against the North after it conducted its fourth nuclear test on 6 January. The North is already under sanctions for its nuclear and missile programs.
North Korea last conducted a long-range rocket launch in late 2012, successfully putting an object into orbit in what is believed by experts to be part of its effort to build an intercontinental ballistic missile (ICBM).
The North is also thought to be working to miniaturize a nuclear warhead to mount on a missile, but many experts say it is still some time away from perfecting the technology, foreign media reports.