North Korea says it has begun fuelling its rocket ahead of a planned - widely criticised - launch.
Paek Chang-ho, head of the satellite control centre of the Korean Committee of Space Technology, said fuel was being injected "as we speak".
Critics fear that the launch, expected between 12-16 April, is a test of long-range missile technology.
It comes as the Worker's Party promoted new leader Kim Jong-un to "first secretary" at a rare meeting.
The party also named his late father, Kim Jong-il, as its "general secretary for eternity", state media said. Kim Jong-il died in December 2011.
Pyongyang says that the rocket will launch a satellite in its quest to peacefully advance its space programme.
"We are injecting fuel as we speak. It has started," Mr Paek told visiting foreign journalists outside the capital, Pyongyang.
"And as for the exact timing of the launch, it will be decided by my superiors."
The journalists were taken on Sunday to the Sohae satellite station at Tongchang-ri, on the country's north-west coast, to see the final preparations.
The launch will also mark the 100th anniversary of the birth of the country's late leader Kim Il-sung.
The North has festivities planned in the lead up to Kim Il-sung's commemoration on Sunday.
Aside from the ongoing meeting of the ruling Korean Worker's Party, an annual session of the parliament to pass new legislation is also scheduled for Friday. Both meetings are expected to further consolidate the transition of power to Kim Jong-un.
Neighbouring countries that may be in the rocket's path have made preparations. South Korea and Japan have said they will shoot down the rocket if it threatens their territory, and the Philippines has re-routed air and sea traffic.
South Korea has also warned the North it risks further isolation if it goes ahead.
US Secretary of State Hillary Clinton said on Tuesday that if the North wanted a "peaceful, better future" for its people it should not launch the rocket, calling the move a direct threat to regional security.
Pyongyang agreed in February to a partial freeze in nuclear activities and a missile test moratorium in return for US food aid. But that deal was put on hold last month after the North announced its rocket launch plans.