JAKARTA (AFP) - Indonesian President Joko Widodo will kick off a visit to Japan and China at the weekend, an official said on Friday, seeking fresh investment from Asia's two biggest economies to boost slowing growth.

Widodo, who took office in October, will arrive in Tokyo on Sunday for a four-day state visit, during which he will meet Prime Minister Shinzo Abe as well as Japanese businessmen.

"It is hoped that there will be a number of agreements related to trade, investment, and most likely... defence cooperation," said foreign ministry spokesman Arrmanatha Nasir.

Japan has been a major investor in Indonesia, Southeast Asia's biggest economy, for decades, ploughing money into a range of sectors, from electronics to the car industry.

Arrmanatha said the agreement on defence would touch on issues including "capacity building, military equipment and peacekeeping".

Widodo will also meet Emperor Akihito during the trip, which will be his first state visit outside Southeast Asia.

During the visit to China, on March 26 and 27, Widodo will meet President Xi Jinping and businessmen, and will also participate in the Boao Forum for Asia, an annual gathering of political and economic leaders.

Arrmanatha said the two-nation tour "will highlight that Indonesia is an important partner for those countries and is ready to open its markets, and to cooperate economically".

Widodo has vowed to boost Indonesia's economic growth, which slipped to its slowest pace in five years in 2014, but needs extra investment to help with an ambitious programme of building new infrastructure.

The president, known by his nickname Jokowi, will also be hoping for some victories abroad after recent trouble at home.

He was criticised for nominating a corruption suspect to be the country's new police chief and has faced mounting international anger over a plan to execute foreign drug convicts.