U.S. Defense Secretary Lloyd Austin met with Cambodia’s prime minister on Tuesday amid growing concern in Washington over Cambodia’s relations with China, with China potentially viewing the country as a base in Southeast Asia.
The defence chief, meeting with Prime Minister Hun Manet for the first time since taking over the premiership from his father, expressed concern about China’s involvement in the naval base that China helped build, a US official told ABC News.
Cambodia, a close ally of China, has allowed a Chinese-funded base to be built in the Gulf of Thailand, and Chinese warships were spotted there last month.
According to the Pentagon, Austin met separately with Manet and his father, Hun Sen, who ruled Cambodia for 38 years. Manet was a graduate of the United States Military Academy at West Point, the first Cambodian officer cadet to graduate from the school, Austin’s alma mater.
Both the US and Cambodia have expressed optimism about the Phnom Penh talks, with the US statement noting there are “opportunities” for cooperation despite work ongoing at the base.
Ahead of the meeting, Deputy Prime Minister Sun Chanthol told ABC News the talks could lead to military-to-military relations, including humanitarian and disaster relief, mine clearance and cooperation in recovering the remains of US soldiers missing in Cambodia.
The Deputy Prime Minister acknowledged that Ream was a military base and said it would be open to foreign naval exercises other than those of China.
“This is definitely not a Chinese facility,” Sun told ABC News in an interview. “We built Ream Naval Base for our own national security.”
“Once completed, any navy in the world can [Ream] Use it for humanitarian aid and disaster recovery,” he said.
Whether Cambodia allows other navies to use the base and whether contractors continue dredging will be crucial in determining whether Ream is a Chinese base, according to an analysis by the Center for Strategic and International Studies. Sun acknowledged that dredging is taking place at the base but reiterated that any navy using the base will not be allowed to use it for military purposes.
“We will not allow any military force to use our territory to attack other countries,” he said, pointing to Cambodia, which co-sponsored a resolution opposing Russia’s aggression in Ukraine.

U.S. Secretary of Defense Lloyd Austin (left) listens to a speech by Cambodian Prime Minister Hun Manet (right) during a conference at the Peace Palace in Phnom Penh on June 4, 2024.
Str/POOL/AFP via Getty Images
“There’s no doubt about where our concerns lie,” a Pentagon spokesman told ABC News.
“Meeting in person will give us the opportunity to articulate our concerns as well as discuss how we can work together to strengthen our relationship going forward,” the spokesperson said.
“And we are not asking any country to choose its partners,” they added.
San said Cambodia’s relations with Beijing and Washington were not a “zero-sum game” and Cambodia could trade with both, adding that the US was already Cambodia’s largest export market.
“We need more investment from the U.S., not less. We need more engagement with the U.S., not less,” said Son, who also attracts foreign direct investment from Japan and Europe.
Cambodia is classified as a least developed country by the United Nations but is on track to graduate from that status by 2029.
“It’s clear that the new prime minister will do a great job of attracting more people. [foreign direct investment] “They came from the West,” said Allen Tang, former president of the American Chamber of Commerce in Cambodia.
Thanh said Cambodia’s regulatory environment was increasingly aligning with Western investors’ expectations, and the United States was already leading the way in mine clearance in Cambodia and globally.
Sun said he hoped Austin and Manet would hold a “heartfelt” dialogue and that Cambodia, suffering from a famine-like situation, was cooperating with Beijing out of necessity.
“China built that port because we don’t know how to build a port,” he said of Liam.
A senior defense official told ABC News that Austin placed a premium on “face-to-face meetings, particularly in the region” and that there was “a lot that the two countries can do together.”
“Cambodia is a young country in a young region. There is a lot of potential and room to grow in our defense relationship,” the official said, referring to the possibility of resuming military training and exchanges.