South Korea called on Saturday for the creation of a global crisis management system to cope with increasingly destructive natural disasters.

"As we have seen with the 2004 tsunami in Southeast Asia, the recent cyclone in Myanmar and the more recent earthquakes in China, natural disasters are hard to predict, and their damage can be even more extensive in the future," Defence Minister Lee Sang-Hee said.

Speaking at the Shangri-La Dialogue international conference on Asian security, Lee said it was difficult for individual nations to "cope with the havoc wreaked by nature" on their own.

"Therefore, a crisis management system of global reach is urgently required to effectively manage the vestiges of natural disasters," the South Korean minister said.

"Working together on such a system will strengthen our regional and global cooperation in dealing with today's uncertainty," he added.

Earlier at the same forum, US Defence Secretary Robert Gates said the Myanmar military junta's delay in allowing international aid into the cyclone-hit country had cost "tens of thousands of lives".

Gates said US ships could have quickly delivered much-needed aid to Myanmar in the aftermath of the May 2-3 storm that left 133,000 people dead or missing.

"Our ships and aircraft awaited country approval so they could act promptly to save thousands of lives – approval of the kind granted by Indonesia immediately after the 2004 tsunami and by Bangladesh after a fierce cyclone just last November," Gates said.

"With Burma (Myanmar), the situation has been very different – at a cost of tens of thousands of lives."

The 8.0-magnitude quake that rocked southwest China's Sichuan province on May 12 has left more than 68,500 people dead while the 2004 Indian Ocean tsunami left a death toll of about 220,000 in a dozen nations, with the largest toll in Indonesia.