WASHINGTON — China is expanding its nuclear force, has increased military pressure against Taiwan and has strengthened its ties with Russia over the past year, according to a Pentagon report Wednesday that details actions accelerating key areas of conflict with the United States.

The report, however, also notes that the recent rash of corruption allegations within China’s powerful Central Military Commission, which oversees the People’s Liberation Army, is hurting Beijing’s military growth and could slow its campaign to modernize.

The impact, said a senior defense official, is a bit of a mixed bag because while there has been progress in some programs, China has slid back in others.

The official, who spoke on condition of anonymity to describe the U.S. assessment, warned that Beijing is working toward developing a more diverse and technologically sophisticated nuclear force. While the expected number of nuclear warheads has maintained consistent growth, China is broadening its targeting abilities.

Beijing is going to be able to go after more and different types of targets, do greater damage and have more options for multiple rounds of counterstrikes, the official said. The U.S. is urging China to be more transparent about its nuclear program, while also warning that America will defend its allies and take appropriate steps in response.

According to the report, which provides the annual U.S. assessment of China’s military power and is required by Congress, China had more than 600 operational nuclear warheads as of May, and the U.S. expects it will have more than 1,000 by 2030.

The Chinese Embassy, in response, said China has always “firmly adhered to a nuclear strategy of self-defense,” follows the no-first-use nuclear policy and maintains its nuclear capabilities at the minimum level required for national security.

Liu Pengyu, the embassy spokesman, said such annual reports by the Pentagon are “filled with ‘Cold-War’ thinking and zero-sum game mentality, which China firmly opposes.”

The Biden administration has worked to maintain a balance with China, building up the U.S. military presence to be ready to counter Beijing while also encouraging increased communications between the two countries at the diplomatic and military levels.

That uptick in talks has coincided with a decrease in coercive and risky intercepts of U.S. aircraft since late 2023, compared with the previous two years. China still, however, does what the U.S. military considers “unsafe” flights near American and allied forces in the region.

The Pentagon’s national defense strategy is built around China being the greatest security challenge for the U.S., and the threat from Beijing influences how the U.S. military is equipped and organized for the future.