Australia will seek to broaden and deepen its security alliance with the United States in the decades ahead as the rise of China and other Asia-Pacific powers risks fueling instability in the region, Australia's defense minister said on Thursday.Foreshadowing a strategic defense white paper due later this year, Kevin Andrews said world economic and military power was shifting to the Asia-Pacific."But growth in the region will be uneven and competition to exert more influence could generate instability," he told US and Australian business leaders in Canberra."Also competing claims for territory and natural resources in the South China Sea will continue to be a source of tension in the region. Combined with growth in military capability, this backdrop therefore has the potential to destabilize the region and threaten Australia's interests."China has been increasingly assertive in the South China Sea, reclaiming land on islands and reefs under its control. The Philippines, Vietnam, Malaysia, Brunei and Taiwan also have overlapping claims in the seas, through which $5 trillion in ship-borne trade passes every year.