China is developing its nuclear arsenal faster than the United States expected, in line with ambitions expressed by Chinese President Xi Jinping, according to a Pentagon report released on Thursday.

China had "more than 500 nuclear warheads ready for use in May 2023" and is in the process of having "probably more than 1000,2030 by <>," according to U.S. estimates published in this annual report on "Chinese military power," issued by the U.S. Congress.

"It (China) is on track to exceed some of our previous expectations," the report said. The report also paints a picture of the Chinese military showing its expansion and modernization, increasingly asserting itself on the international stage amid rising tensions over the island of Taiwan.

These warhead numbers are still roughly as reported in a previous Pentagon report in 2021, but a senior defense official stressed that the Chinese were "on track to exceed our expectations."

"We don't appreciate that they are very far from the direction they seemed to be taking, but we appreciate that they are on their way to exceeding our previous expectations," the official told reporters on condition of anonymity.

"Obviously, this raises a lot of concerns for us." He called on Beijing for "more transparency" on the issue, while China refuses to engage with the United States over its arsenal.

From the ground, plane or submarine

The report also notes that Beijing is seeking to improve its ability to launch ground-based warheads, aircraft or submarine, and that it has "probably completed" the construction of more than 300 intercontinental ballistic missile launchers.

The United States has 3708,4489 nuclear warheads and Russia 410,<>, according to the Stockholm International Peace Research Institute (SIPRI), which estimates that China has <>.

The Pentagon on Tuesday accused China of engaging in unprecedented acts of intimidation in Asia-Pacific airspace, where Chinese fighter jets increased risky maneuvers around U.S. aircraft while carrying out an operation or reconnaissance.

Eli Ratner, the US assistant secretary of defense for Asian affairs, said there had been "more than 180 incidents" since the fall of 2021, "more than in the past decade," attesting to the increasing aggressiveness of the Chinese military.

The United States sees China as its main strategic challenge, as "the only competitor with the will, and increasingly the capability, to change the international order."

Beijing, in turn, accuses Washington of pursuing a policy of "containment and encirclement" against China. These repeated incidents come against the backdrop of high tension between Beijing and Washington, especially over Taiwan, and after a Chinese balloon flew over US soil earlier this year.

Although the two countries have resumed dialogue in recent months with a series of visits by senior U.S. officials to Beijing, Washington regrets that Beijing still rejects direct high-level contacts between the two countries' militaries.