South Korean space officials suspended a crucial rocket launch Thursday, after a technical problem halted the countdown just 17 minutes before the scheduled blast-off.

"It is impossible to resume the launch sequence today," Deputy Science Minister Cho Yul-Rae told reporters at the Naro Space Center on the south coast.

Cho declined to speculate on the duration of the delay, but officials said the rocket would have to be removed from the launch pad, suggesting it would be at least several days before a new attempt can be made.

It was to have been South Korea's third attempt to put a satellite in orbit and gain entry to an elite global space club that includes Asian powers China, India and Japan.

After successive failures with the same 140-tonne Korea Space Launch Vehicle (KSLV-1) in 2009 and 2010, the current mission is seen as crucial to the future of South Korea's space programme.

It was the second time this launch had been suspended.

Originally scheduled for October 26, it was delayed by more than a month after engineers detected a broken rubber seal in a connector between the launch pad and the first stage.

Cho said the problem this time around appeared to lie with the propulsion system of the rocket's second stage.

The KSLV-1 has a first stage manufactured by Russia and a solid-fuel second stage built by South Korea.

"It is very regrettable that people's expectations have not yet been met," Science Minister Lee Ju-Ho told reporters,

"We will thoroughly check the problem and we will spare no effort to make the launch a success this time," Lee said.

The official launch window is set to close on December 5, and Kim Seung-Jo, president of the Korea Aerospace Research Institute, said it was too early to say if another launch could be attempted in time.

A late entrant into the high-cost world of space technology and exploration, South Korea is desperate to get its commercial launch programme up and running.

Seoul's space ambitions were restricted for many years by its main military ally the United States, which feared that a robust missile or rocket programme would accelerate a regional arms race, especially with North Korea.

Japan and China both achieved their first satellite launches back in 1970, and India made its breakthrough in 1980. But the lack of US support contributed to South Korea, Asia's fourth largest economy, lagging behind.

Soon after joining the Missile Technology Control Regime in 2001, South Korea made Russia its main space partner.