North Korea has tried to import missile technology from Ukraine and other countries, the government here believes.
A senior South Korean official said after failing four times so far to launch a rocket into space, the North turned to foreign technology and experts. "It appears that a missile expert of unclear nationality recently made a secret visit to the North," the official added on condition of anonymity.
The South Korean government believes North Korea used foreign help to solve problems like weak engine thrust, and that there is a significant chance that the upcoming missile launch scheduled for sometime this month will be successful.
The North says the aim is to put a satellite into orbit, but the international community believes this is merely a cover to test long-range missile technology.
Last year, two North Korean agents were arrested in Ukraine and sentenced to eight years in prison for trying to smuggle out classified documents about fuel supply systems, liquid-fuel engines and rocket design.
Some 70 percent of the Soviet Union's intercontinental ballistic missile production took place in Ukraine.
On Saturday, North Korea's official KCNA news agency announced the launch between Dec. 10 and 22 of a satellite built with homegrown technology "upholding the legacy of comrade Kim Jong-il."
The launch will take place at a missile base along its west coast. The first stage will separated over the Byeonsan Peninsula and the second stage will fall in the high sea east of the Philippines.