SEOUL : North Korea 's widely-condemned launch of a long-range rocket could happen within a matter of hours, after Pyongyang shortened and brought forward the start of the launch window to Sunday morning.

An updated notification sent by Pyongyang to UN agencies on Saturday -- a copy of which was released by the South Korean government -- said the launch would now take place between February 7-14. The initial window announced by the North on Tuesday had been February 8-25.

The planned satellite launch has been slammed by the international community as a disguised ballistic missile test that amounts to another serious violation of UN resolution, following the North's nuclear test last month. The brief updated notice sent by Pyongyang offered no reason for the date change.

Any launch would now take place before the February 16 birthday of late leader Kim Jong-Il, the father of current leader Kim Jong-Un.

The North insists its space programme is purely scientific in nature, but the United States and allies, including South Korea, say its rocket launches are aimed at developing an inter-continental ballistic missile (ICBM) capable of striking the US mainland.

UN sanctions prohibit North Korea from any launch using ballistic missile technology. While the prospective launch dates were changed, there was no amendment to the 7:00am-midday (2230-0330 GMT) daily window. That means the rocket could blast off during the biggest annual US sports event of the year -- the Superbowl, which kicks of at 8:00am Monday, Pyongyang time.