The Defense Ministry said Friday that a delivery of U.S.-made vehicles to equip Japan's new amphibious unit has been delayed just months ahead of its debut.

The new Ground Self-Defense Force unit, modeled after the U.S. Marine Corps, was expecting 30 AAV-7 amphibious vehicles from BAE Systems Inc. by the end of November. Instead, the new amphibious brigade may only have seven when it launches in March.

The purpose of the amphibious brigade is to counter attacks on Japanese islands stretching from Kyushu southwest toward Taiwan as China grows increasingly assertive on the seas.

A total of 52 AAV-7s are to be supplied to the 2,100-member brigade by March 2020. The unit is to be stationed mainly at Camp Ainoura in Sasebo, Nagasaki Prefecture.

The AAV-7s are used by the U.S. Marines and can operate in water and on land. Each one can carry up to 24 soldiers.

According to the ministry, a fire at a BAE Systems subcontractor, along with a parts shortage, has delayed delivery of the first 30 vehicles. Half are now to be supplied by the end of March and the other 15 by the end of July, the ministry said.

The vehicles will then need to undergo modification for use on public roads in Japan, a ministry official said.