PHNOM PENH -- The U.S. defense attache to Cambodia abruptly ended a tour of Ream Naval Base on Friday after being denied "full access" to the site, which is undergoing Beijing-backed expansion.
Col. Marcus M. Ferrara canceled the inspection after a "brief visit" to the base, situated on Cambodia's coast on the Gulf of Thailand, according to a statement from the U.S. Embassy in the country.
"Cambodian military officials refused to allow the defense attache full access to the naval base," the embassy said. "When it became clear he would not be granted adequate access, Col. Ferrara ended the tour and requested Cambodian military officials reschedule the visit with full access at the earliest opportunity."
The embassy added that "routine and frequent visits by U.S. and other foreign military attaches to Ream Naval Base can be an important step towards greater transparency and mutual trust."
The tour had been organized following a visit by U.S. Deputy Secretary of State Wendy Sherman on June 1. Sherman told Cambodian Prime Minister Hun Sen that Washington has "serious concerns" about China's "military presence" at Ream.
Beijing is helping to expand the port, dredge shallow waters surrounding the base and construct a ship repair facility. But Hun Sen and Chinese leaders have repeatedly denied there are plans to host Chinese military assets at the base.
Calls to Cambodia's Minister of Defense Tea Banh went unanswered on Friday. Military spokespeople were also unreachable.
As recently as Wednesday, Banh reiterated the government's position that Cambodia would not allow any foreign countries to establish a military base on its soil.
The U.S. Embassy declined to answer further questions about what area of Ream was kept off-limits and whether it could provide more detail about the Chinese military presence alleged to be there.
Reached on Friday, government spokesman Phay Siphan said Cambodia had "nothing to hide" but said some parts of the base were off-limits because of national security.
He pointed out a similar arrangement existed in the U.S. "The U.S. itself never allows anyone" unrestricted access to its bases, he said, adding the U.S. was welcome to re-apply for a future visit.
"I believe the U.S. understands clearly Cambodia's sovereignty and security."