The U.S. military is no longer the primary force in Asia, and missiles from China's rapidly improving military could overwhelm its bases in hours, CNN says citing a new report.

The study by the United States Study Center, at the University of Sydney, in Australia, warned that America's defense strategy in the Indo-Pacific region "is in the throes of an unprecedented crisis" and could struggle to defend its allies against China.

That means Australia, Japan and other U.S. partners need to build up and refocus their forces in the region, and consider increased cooperation with the U.S., to ensure their security, the study claimed.

The report highlights areas where China's military is making huge strides in comparison to the U.S. and its Asian allies and partners. Chief among those is in missiles.

"China has deployed a formidable array of precision missiles and other counter-intervention systems to undercut America's military primacy," the report states. Those missiles number in the thousands, the report says.

Almost all U.S. military installations in the Western Pacific, as well as those of its key partners and allies, "could be rendered useless by precision strikes in the opening hours of a conflict," according to the report.

China's Foreign Ministry said Monday it had not seen the report, but spokesperson Geng Shuang stressed that the country's military policy was "defensive in nature."

"China is firmly on a path of peaceful development and our national dense policy is defensive in nature," Geng said.