Washington has provided ally Manila with military support in the past, including a warship offered last month as part of a USD 250-million aid package to Southeast Asian nations.
Seventy-seven M113A2 of the donated armoured personnel carriers (APCs) arrived late Wednesday and the rest will come next month, the US embassy in the Philippines said in a statement.
The donation boosts the Philippine army's inventory of armoured vehicles by over a third to 455, said spokesman Colonel Benjamin Hao.
"Our forces are now more protected and they will have more mobility because they will be in a tracked vehicle," that is more suited for rough terrain, he told AFP.
He would not specify where they would be sent, only that "they will be in areas where they are needed".
The vehicles were offered as part of a US military programme of giving away excess equipment, but the Philippines paid 67.5 million pesos ($1.4 million) to cover transport costs, officials said.
Philippine President Benigno Aquino has sought to modernise the armed forces by acquiring new ships and aircraft in recent months.
Aquino has proposed to parliament a 25 per cent hike in defence spending next year to a record 25 billion pesos (USD 552 million).
Earlier this year, the military received 28 M113A2 vehicles, many refurbished with cannons and remote-controlled turrets, from Israel.
