The Philippines is set to destroy five tonnes of elephant tusks on Friday in a high-profile event aimed at shedding its image as one of the world's worst hotspots for illegal African ivory trading.

Environment department officials are scheduled to use a road roller to crush the so-called "blood ivory", becoming the first country in Asia to destroy its multi-million-dollar stockpile.

"We want to send a message to the world that... we are very much against the illegal ivory trade," the director of the government's Protected Areas and Wildlife Bureau, Theresa Mundita Lim, who will oversee the event, told AFP.

The five tonnes of tusks come from a total of 13.1 tonnes seized at Manila's port and international airport after being smuggled in from Africa in 2005 and 2009.

The rest of the ivory, worth many millions of dollars on the black market, was stolen over the years.

Most of it went missing while being kept by the customs bureau, a notoriously corrupt organisation in the Philippines, and a wildlife bureau officer is on the run after being charged with stealing about 700 kilogrammes.

The Philippines was in March named by the Convention on International Trade in Endangered Species (CITES) as one of eight nations that was failing to do enough to tackle the illegal trade in elephant ivory.

The others were Kenya, Tanzania, Uganda, Malaysia, Vietnam, China and Thailand, and they were warned they could face international sanctions on wildlife trading if they failed to take action.

All countries have since submitted their action plans on how they intend to curb the trade, which is leading to the slaughter of thousands of elephants each year, although those reports have not been made public.

The Philippines was named because of its role as a transport hub for African ivory being smuggled into countries such as China, Vietnam and Thailand, where demand has skyrocketed in recent years.

The ivory is highly sought after for statues, trinkets and other items to showcase wealth.

Demand is also high in the Catholic Philippines, with the ivory used for religious icons.

Lim said the destruction of the ivory was one part of the government's action plan submitted to CITES.

She said another element was the imminent establishment of a multi-government-agency taskforce focused solely on the ivory trade.

The executive director of the London-based Environmental Investigation Agency, Mary Rice, praised the Philippines for taking the lead in destroying its stockpiles.

"This is a really significant event. It is the first time a consuming country and an Asian country has decided to dispose of its seized stockpiles," Rice, who is in Manila to witness the event, told AFP.

Rice said thousands of tonnes of seized ivory were sitting in storehouses in other cities around Asia and other parts of the world.

Some African nations have previously burnt ivory stockpiles, most recently Gabon last year.

The United Nations and conservation groups warned in a major report in March that African elephants faced the worst crisis since global trade in ivory was banned almost a quarter-century ago.

The report warned the risk of extinction was rising sharply in some nations.

Illicit trade in ivory had doubled since 2007 and more than tripled over the past 15 years, according to the report, which estimated that only about 420,000 to 650,000 elephants remained in Africa.

About 25,000 African elephants were estimated to have been killed for their ivory in 2011, the report said, and conservationists believe last year was even worse.