TOKYO - JAPAN will send a warship to the pirate-infested waters off Somalia as early as April, a newspaper said on Thursday, as shipping industry leaders pressed the government to take immediate action.

Prime Minister Taro Aso will authorise a plan within the month for a destroyer to head to the waters off the lawless African nation, the Nikkei business daily said, citing unnamed sources.

Mr Aso last month ordered his cabinet to study drafting a law for a Somalia mission. A defence ministry spokesman, asked about the report, said no timeline had been decided.

A number of nations are sending ships to the area to fend off increasingly brazen pirate attacks, which have led some shipping companies to avoid the route via the Suez Canal and, at greater cost, sail around Africa instead.

But Japan, officially pacifist since World War II, can legally only use its navy to protect Japanese vessels and citizens.

The Nikkei said Mr Aso would define the Somalia mission as defending Japanese ships, with the destroyer's use of force limited to self-defence and emergency evacuations.

The Japanese Shipowners' Association called on Thursday for the government to send a ship as soon as possible.

'Right at this moment ships and their crew members are being threatened by pirates,' it said in a statement.

'Even if the dispatch will be limited to escorting (ships), we can expect an effect in stopping piracy activities and give a sense of security to crew members,' wrote chairman Hiroyuki Maekawa.

The United States has encouraged Japan to join anti-piracy operations.

China, Japan's neighbour and sometime rival, in December sent three vessels, marking the first time in recent history that the communist giant has sent ships far from its territory for a potential combat mission. -- AFP