SINGAPORE - A volcanic eruption followed by a major typhoon hitting the Philippines within five days. It is a disaster requiring assistance from around the world. But who will coordinate the effort and how will they make sure their resources don't overlap?

Militaries from 18 countries around the world have been gathered at Changi Naval Base over the last three days (Jan 23 to Jan 25) to plan the humanitarian and disaster relief response to this simulated scenario.

The exercise, codenamed Coordinated Response, is jointly organised by the Armed Forces of the Philippines, the US Centre for Excellence in Disaster Management and Humanitarian Assistance, and the Singapore Armed Forces' (SAF) Changi Regional Humanitarian Assistance and Disaster Relief Coordination Centre.

Besides the 18 militaries from countries such as China, Vietnam, Britain, and Malaysia, another 12 civilian organisations such as Doctors Without Borders and the Singapore Red Cross Society are also taking part as observers.

Defence Minister Ng Eng Hen, who was visiting the exercise area with Philippine Defence Secretary Delfin Lorenzana, said it was "important to have a network of partners, both military and civilian who were used to working with each other so that you can respond very effectively in the first 48 to 72 hours".

Mr Lorenzana noted that the exercise was a valuable chance to learn from one another, particularly as his country faces a high number of typhoons in any given year.

Colonel Lee Kuan Chung, one of the directors of the exercise, said such exercises mean that those who want to offer help when disaster strikes know who to reach out to in the affected country.

"Building relationships, knowing each other is important so that we don't exchange name cards during the operation... We can exchange name cards right now," he said.