Two Chinese Liberation Army's Navy corvettes are docked at the Ream Naval Base in Cambodia.
CNN  — 

Chinese warships have docked for the first time at Cambodia’s Ream Naval Base, which is undergoing a Chinese-funded upgrade that has drawn concerns from the United States over its potential role in expanding China’s overseas military footprint.

Cambodia’s Defense Minister Tea Seiha visited the Chinese People’s Liberation Army (PLA) Navy warships docked at the Ream port on Sunday along with his father – and predecessor – Tea Banh, according to a post on the official’s Facebook page.

While the post did not specifically mention the Chinese military, the accompanying photos showed two PLA Navy corvettes docked side by side. On board one of the corvettes, identified as the “Wenshan” on the vessel’s gangplank, Tea Banh reviewed a row of Chinese naval officers.

The ships are in preparation for training the Cambodian navy, according to the post.

Other photos in the post show the father and son inspecting infrastructure construction on the site and viewing a design plan of the project.

Collin Koh, research fellow at the S. Rajaratnam School of International Studies (RSIS) in Singapore, said according to public records, this is the first time PLA Navy ships have docked at the port, which before renovation was only fitted for the Cambodian Navy’s smaller patrol crafts.

“It is a signal that Ream is about to be completed. Of course, it’s still work in progress for them, but at least now, it has expanded to the point that it could accommodate a foreign navy ship,” he said.

John Bradford, executive director of the Yokosuka Council on Asia-Pacific Studies, said it is no surprise that Chinese ships were the first to visit the upgraded base.

“After all, the facilities were funded by the Chinese and China is a close partner to Cambodia,” he said.

The visit of Chinese warships coincided with a top Chinese general’s trip to Phnom Penh, where he hailed China and Cambodia as “true ironclad friends.”

He Weidong, a vice chairman of China’s top military body, the Central Military Commission, told Cambodian Prime Minister Hun Manet that the two countries’ militaries have sustained “high-level cooperation in fields including high-level exchange, mechanism building, joint drills and exercises, and personnel training,” according to a Chinese readout of the meeting.

Hun Manet, who succeeded his father Hun Sun earlier this summer, thanked the Chinese military for its “strong support for the modernization of the Cambodian army,” according to the statement posted on the Chinese Defense Ministry’s website.

The Chinese general also held talks with Tea Seiha, the Cambodian Defense Minister, to exchange views on “bilateral relations, military cooperation, and international issues of common interest,” according to the readout, which did not mention the visiting PLA Navy warships.

CNN has reached out to China’s Ministry of Defense for comment.

A US State Department spokesperson said Washington was monitoring reports of the Chinese warships, according to Reuters. “While we have no comment on this specific development, we have serious concerns about the PRC’s plans for exclusive control over portions of Ream Naval Base,” the official told Reuters, referring to China by its official name, the People’s Republic of China.

Tea Banh, former Cambodian Defense Minister, reviews Chinese naval officers on board a Chinese corvette at the Ream Naval Base.

Heightened concerns

The unprecedented presence of Chinese navy ships at the Ream Naval Base, which occupies a strategic position near the southern tip of Cambodia close to the South China Sea, is likely to deepen long-standing concerns among US officials that China is seeking a military outpost in the Gulf of Thailand.

Such concerns were already heightened in June last year, when Chinese and Cambodian officials presided together over a ground-breaking ceremony for a project to renovate the port with grant aid from China.

Cambodian officials have repeatedly denied the facility would be used by China as a naval base, insisting the project is in line with Cambodia’s constitution, which bars foreign military bases on its territory. Chinese officials, meanwhile, have described the base as an “aid project” to strengthen Cambodia’s navy and called assertions otherwise “hype” with “ulterior motives.”

For the US, the Chinese-funded expansion at Ream is particularly troubling as it involved the demolishing of a US-funded facility there — a development that served as something of an analogy for Cambodia’s closer ties with Beijing and growing distance from Washington, according to Bradford at the Yokosuka Council.

For some, the visiting Chinese navy ships have raised new alarms.

“The arrival of these Chinese warships at Ream exposes China’s long-concealed military aims, marking a major evolution in China’s regional defense posture. To continue dismissing China’s expanding military footprint is to indulge in self-delusion,” said Craig Singleton, a senior fellow at the Washington-based think tank the Foundation for Defense of Democracies.

Singleton, who wrote an analysis on Beijing’s growing push for overseas port access earlier this year, said China’s presence at the Ream Naval Base is part of a broader plan to complicate America’s global military calculus.

“By building closer military ties and economic dependencies with select countries along major maritime routes, Beijing can exert diplomatic pressure on them, limiting U.S. basing access and complicating coalition-building efforts to support Taiwan’s defense should China ever invade,” the self-ruled island Beijing claims as its own, he said.

Alongside Djibouti in East Africa, Beijing’s sole military base overseas, Ream “signals more than just a cost-effective extension of China’s defense perimeter, but a calculated, assertive repositioning with grave implications for Washington and its allies.”

But other experts have noted that the level of access the PLA is granted at Ream could be very different from its base in Djibouti, where Chinese troops can be permanently stationed at onshore facilities. That arrangemen