The move comes amid a lingering dispute with Thailand. The neighboring nations have had several small but deadly skirmishes over conflicting claims to a border dispute.
Military and political officials kept anonymous by the People's Daily said nearly 100 tanks and armored personnel carriers were shipped off Sihanoukville Sea Port Monday and will later be taken to Phnom Penh.
A spokesman for Cambodia's Ministry of Defense, Chihum Socheat, confirmed the arrival of the military trucks but refused to give exact number and other details. By some accounts 94 armored vehicles were delivered.
Separately, the People's Daily reported that Sihanoukville Sea Port officials spotted "around 50 tanks and 40 armored personnel vehicles and a few other military trucks."
They claimed the military equipment had been "shipped on a large vessel."
Sihanoukville Sea Port is in Sihanoukville Province, a coastal area and is about 180 miles southwest of Phnom Penh.
"We will have many more" than 94, Koy Kuong, the foreign ministry spokesman was quoted saying to local media.
"We have purchased this equipment in order to strengthen our military capacity to defend territorial integrity and to prevent any intentional invasion from another country," the spokesman said.
He refused to disclose how much Cambodia would be paying for the new hardware and the Eastern European state supplying Phnom Penh. Russia, where Cambodian military have been trained in the past, hasn't been ruled out.
London's International Institute of Strategic Studies estimated the strength of Cambodia's armed forces at 123,300 in 2010. That is about 150,000 fewer than its hostile neighbor, Thailand, which also boasts a well-equipped air force.
Since relations between the two countries took a turn for the worst as a result of the deadly clashes, Cambodia has mounted efforts to boost and eventually match its defense capabilities with Thailand's.
The border dispute stems from conflicting claims to a region housing the ancient Preah Vihear temple which was granted World Heritage status by UNESCO two years ago.
Under a ruling by the World Court in 1962, the temple was found to belong to Cambodia although its main entrance stands in Thailand's territory.
Since the clashes, Thai troops have built 20 large bunkers to strengthen their positions on the border against any Cambodian troop incursions. The border has never been fully demarcated.