US President Barack Obama has said that the Asia-Pacific region will play a key role in defining the world's future. "The United States is a Pacific power, and we are here to stay," he stated in a speech to the Australian parliament, sending a clear message to Beijing. His comments came after Australia agreed to host a full US Marine taskforce in the coming years. China has questioned the move, which many analysts see as being a counter to Beijing's growing influence. Speaking in Canberra, Mr Obama said the US was now turning its attention to the region. "Let there be no doubt: in the Asia-Pacific in the 21st Century, the United States of America is all in," he said. Key player Mr Obama said that given its size, resources and the economic growth that the region had witnessed in recent years, Asia-Pacific countries were playing an increasingly important role globally. "With most of the world's nuclear powers and some half of humanity, Asia will largely define whether the century ahead will be marked by conflict or co-operation, needless suffering or human progress." "As a Pacific nation, the United States will play a larger and long-term role in shaping this region and its future by upholding core principles and in close partnership with our allies and friends." Mr Obama said that, as the world's biggest economy, the US was keen to increase its presence in the region and play a bigger role in its development and progress. At the same time he told the Australian parliament that the US was working towards getting its own economy back on track. He said the US had taken some hard decisions to cut its deficit and will continue to do more to ensure that growth rebounded. China factor Mr Obama underlined that the alliance between the US and Australia was an indispensable one and had never been stronger. However, the growing proximity - especially a bigger US military presence in Australia - has not gone down well with China. The US president used his speech in Canberra to emphasise a willingness to co-operate with Beijing and improve communication between the superpowers. "We've seen that China can be a partner, from reducing tensions on the Korean peninsula, to preventing proliferation," he said. "We'll seek more opportunities for co-operation with Beijing, including greater communication between our militaries, to promote understanding and avoid miscalculation." However, Mr Obama called upon the authorities in Beijing to change their policies as well. "We will do this, even as [we] continue to speak candidly with Beijing about the importance of upholding international norms and respecting the universal human rights of the Chinese people," he added. Seeking stability The agreement to increase the US military presence in Australia comes at a time when nations in the region are becoming wary of China's growing military might and its domination of the Pacific waters. Australia's Prime Minister Julia Gillard said that maintaining peace and stability in the region was key to its economic growth and success. Ms Gillard added that the partnership between Australia and the US had been a "bedrock of stability" in the region. There are concerns that, as the US tries to cut its defence spending in a bid to reduce its debt, it might reduce its presence in the region. However, Mr Obama tried to quell those fears, saying that he remained committed to the region. "Reductions in US defence spending will not - I repeat - will not come at the expense of the Asia-Pacific," he said. "My guidance is clear - as we plan and budget for the future we will allocate the resources necessary to maintain our strong military presence in this region. "We will preserve our unique ability to project power and deter threats to peace. "We will keep our commitments, including our treaty obligations to allies like Australia, and we will constantly strengthen our capabilities to meet the needs of the 21st century."