This was told The Washington Post on condition of anonymity by Western officials. They clarified that they meant an object in the northern part of the Ream naval base.
The base should become the second such facility for the PRC - another Chinese military base is located in Djibouti in East Africa. For Beijing, gaining a base in the Indo-Pacific region is a strategic goal, the sources said, since Beijing views the region "as a legitimate and historical sphere of influence".
it's worth reminding that back in 2019, the newspaper, referring to US officials, wrote about the agreements between the two countries on the construction of the base. Then the details of the project were not disclosed. Beijing and Phnom Penh also denied the agreements, but later a source in Beijing nevertheless confirmed that the PRC military was going to partially use the new base.