The 33m-high KSLV-1 is South Korea's first space rocket
South Korea has called off the launch of its first space rocket just minutes before the scheduled blast-off due to a suspected problem with fuel pressure.
Officials said an automatic abort system was triggered during the countdown when weak pressure was detected in a fuel tank.
It will now be several days before another launch can be attempted.
The rocket, intended to place a satellite into orbit, has been developed with the help of Russia.
The two-stage Korea Space Launch Vehicle-1 (KSLV-1), was set to blast off on Wednesday from the Naro space complex, 475km south of Seoul.
But the countdown was halted just eight minutes before lift-off.
"The automatic launch sequence automatically turned off due to a problem that was detected in the countdown," said Lee Sang-mok, the deputy minister of science and technology policy.
He said a valve had not functioned because of weak pressure inside one of the fuel tanks.
The fuel would be extracted, a process that takes several days to complete, Mr Lee said.
New space race?
The launch, when it is again attempted, will be monitored by rival North Korea, which has been criticised by the international community for pursuing its own rocket programme.
Earlier this year, the North announced it had successfully orbited a satellite, but the claim was dismissed by the US, Japan and South Korea who called the April flight a cover for a test of ballistic missile technology.
The KSLV-1 is 33m long and weighs some 140 tonnes. Its Russian liquid-fuelled first-stage is said to produce 1,700 kilonewtons of thrust at launch.
The second stage, which burns a solid fuel, was produced by South Korean engineers. It is intended to generate 80kN of thrust and is designed to place the Earth observation satellite into its final orbit just a few hundred kilometres above the planet.
South Korea wants to develop an advanced space programme to compete with other Asian space-faring nations - China, Japan and India.
It has already launched 10 indigenously produced satellites on other countries' rockets.
In April last year, Seoul sent its first astronaut into space aboard a Russian Soyuz rocket.
Yi So-Yeon spent 11 days on the International Space Station, carrying out experiments for the government and industry.