North Korea has readied a rocket for launch, which will showcase the reclusive state's ability to fire a missile with the capacity to hit the continental US.
Pyongyang says the rocket, to be launched this week, will only carry a weather satellite, but South Korea and the US say it is a test of a ballistic missile.
Although the risk of it veering off course is low, guidance remains its weakest point.
In a rare move, reporters were taken to the new Sohae launch station, close to the border with China, where work was in progress to ready the 30-metre high Unha-3 rocket and its satellite.
The three-stage rocket was on the launch platform, indicating the launch will go ahead on plan between 12-16 April.
"Supreme Commander Kim Jong-un made a very bold decision, that is why you are allowed to be this close to the launch site," site director Jang Myong Jin told visiting foreign journalists.
North Korea announced plans to launch the satellite-bearing rocket to coincide with the 100th birthday celebrations of its founder, Kim Il-sung, a move that will help cement the prestige of his grandson Kim Jong-un, who took power in December.
The second stage booster is planned to separate in the seas to the west of the Philippines, about 3,000km from the launch site, and experts say that represents the first possible landfall for the rocket if things go wrong.
If North Korea does achieve a successful separation of the third stage - something it says it achieved in 2009, but most experts say failed to put a previous satellite into orbit - that would show it had improved its technology and the capacity to produce a missile that could carry an intercontinental nuclear warhead.
Pyongyang has also shifted its launch site, and the new, more sophisticated site on the west of the Korean peninsula reduces the risk of debris falling on Japan, which was overflown in a previous test-launch of a missile.
This launch will take the rocket down the west coast of the Korean peninsula. Japan, which fears a repeat of a 2009 firing over its territory, has put its missile batteries on alert to shoot the rocket down.
"They have come pretty far on the question of range, but they still need a lot to resolve in the precision technology needed for [warhead] re-entry and guidance," a South Korean military official who spoke on condition of anonymity said.
The new rocket is believed to have a design range of more than 6,700km, and can carry a payload of up to 1,000kg.
At its closest point, Alaska in the US is about 5,000km from North Korea.
The launch will be the first at the Sohae rocket station, construction of which began in 2007.
It is a large, sophisticated facility with specialised assembly and transport, according to analysis from military specialist consultancy IHS Jane's Defense Weekly.
