China is expected to overtake the US as the world's largest economy a few years before 2030, while the US will remain the top player in the following two decades thanks to its dominant role in international politics, its technological prowess and its soft power that attracts outsiders, said the latest report released on Monday by the US National Intelligence Council (NIC).

"Asia will have surpassed North America and Europe combined in terms of global power, based upon GDP, population size, military spending, and technological investment" by 2030, the 137-page report said.

Meanwhile, the economies of Europe, Japan, and Russia are likely to continue their slow relative declines, it added.

The report, published every four years, is the fifth installment of the NIC's series, based on numerous meetings with experts "far beyond Washington DC."

The NIC's office is set in the Central Intelligence Agency and also includes other intelligence services with the task of working on medium- and long-term strategic reports. But the views presented by the NIC are not limited to US intelligence departments. It consults with a wide range of scholars, including some from China, said professor Wu Xinbo from the Center for American Studies at Fudan University.

The NIC report also predicted that no leading power would be likely to replace the US as a guarantor of the international order because of the US' preeminence across a range of power dimensions and the long period in which it has occupied the leading position.

A Chinese military strategist from the military said the NIC was "excessively humble" in assessing the US role in the following decades.

"The US is transforming its approach in maintaining its leading role in the world," said the strategist who requested anonymity. "Yes, China will surely become the largest economy thanks to it having the world's largest population. But this must not be interpreted as economic power because China will still be a supplier to the US in terms of the international division of labor in the long run."

"There is no reason for the US to cut off its wealth source as long as China maintains strong economic growth and continues to serve as a supplier to the US," he said.

Wu said this is not the first report to predict that China's economy will surpass that of the US. The only difference is the prediction of when it will happen.

"The report will help the US adapt to a multi-polarizing world," Wu said. "And it also noted that the power gap between the US and China is shrinking, which underscores the competition dimension of China-US relations and impacts the US judgment of China's foreign and security polices."

The report said India could become an economic powerhouse and close the gap with China by 2030, as China's economy slows down.

The NIC also predicted that the world population will have reached "somewhere close to 8.3 billion," up from 7.1 billion in 2012, and 80 percent of armed and ethnic conflicts will occur in nations with youthful populations.

The Middle East "will be a very different place" in 2030 because the young bulge - the driving force behind the recent Arab Spring - will give way to a gradually aging population, it said.

But chronic instability will be a feature of the region because of the growing weakness of states and the rise of sectarianism, Islam and tribalism. The challenge is particularly acute in Iraq, Libya, Yemen and Syria, which could break up for a second time.

Agencies contributed to this story