The Singaporean embassy declined to respond to questions about what its government would pay for and how much it would spend, instead referring Fairfax Media to a government statement that provided no details. Bad habits: Prime Minister Malcolm Turnbull has not been able to resist the spin doctors. Credit:Louie Douvis Experts are overwhelmingly seeing the deepening of the defence relationship between Australia and Singapore at least in part as a response to the uncertainty caused by the rise of China. Former trade minister Andrew Robb said on Friday however that "you can increase your relationship and friendship with one country without diminishing your relationship and friendship with another one". Peter Jennings, executive director of the Australian Strategic Policy Institute, said the move – which he called "very positive" – was motivated on Singapore's side by concerns that the Association of South East Asian Nations was struggling to respond to China's behaviour on issues such as the South China Sea.

"They wouldn't say this publicly but they are concerned about ASEAN's inability to come up with a coherent and consistent response to China. They think they can actually now extract more value from the bilateral relationship with Australia," he said. He said China had split off countries such as Cambodia and Laos within ASEAN and this "worries Singapore enormously". Tim Huxley, executive director of the International Institute of Strategic Studies in Singapore, said the two countries were "natural partners" and had "similar concerns" about security in Asia including China's behaviour in the region. "It's similar in that Singapore is concerned about what China is doing in the South China Sea. That has become a bit of an irritant in their bilateral relationship," he said. "At the same time Singapore wants to maintain the best possible relations with China as well as the US. It's a difficult balancing act because Singapore is a bit closer to the front line than Australia."

Defence officials appearing before a Senate hearing confirmed that Singapore has agreed to pay for any upgrades needed to allow their expanded training activities in Australia. They said much of the detail about what would be needed was still to be agreed upon, though the money would be used for infrastructure such as roads, accommodation and the training ranges themselves. Mr Robb has said Singapore would invest $2.25 billion and Mr Turnbull said on Friday the country was "expecting to spend $2.25 billion" but Fairfax Media understands the agreement is actually for up to $2.25 billion. Follow us on Twitter