The United States has placed China as the greatest challenge to the country's security in its new defense strategy report, despite Russia's invasion of Ukraine.

The Defense Department released the 2022 National Defense Strategy on Thursday.

The document points out that China has expanded and modernized its military with a focus on offsetting US military advantages. It says "the most comprehensive and serious challenge" to US national security is China's "coercive and increasingly aggressive endeavor to refashion the Indo-Pacific region and the international system to suit its interests and authoritarian preferences."

The report says the Pentagon prioritizes China's challenge in the Indo-Pacific region, then the Russian challenge in Europe.

It also says the US collaboration with its allies and partners will cement joint capability with the aid of multilateral exercises, technology co-development, greater intelligence sharing and combined planning for shared deterrence challenges.

The Pentagon also released a nuclear posture review, which notes that strategic deterrence remains a top priority mission for the US.

The review recognizes growing concerns about nuclear and missile developments in China, North Korea and Russia. It says the US is committed to strengthening deterrence in ways that are responsive to changes in the regional security environment.

The report notes that the US will strengthen "extended nuclear deterrence." It says US allies and partners can be confident that the US is willing and able to deter the range of strategic threats they face whether in crisis or conflict.