Africa will be an engine for world growth in coming decades, Japan's premier said Monday, wrapping up a meeting that saw Tokyo pledge huge aid as it tries to match China's growing involvement in the continent.

Shinzo Abe said Africa would be at the leading edge of economic expansion and Japan must make a commitment in a way that would benefit both sides.

"Africa will be a growth centre over the next couple of decades until the middle of this century... now is the time for us to invest in Africa," Abe told a press conference at the end of the three-day Tokyo International Conference on African Development (TICAD) in Yokohama near the capital.

"Japan will not simply bring natural resources from Africa to Japan. We want to realise industrialisation in Africa that will generate employment and growth," Abe said.

"The type of growth the TICAD recognises is not just figures... it (aims to) achieve high-quality growth by distributing benefits widely and deeply among people in the society," he said.

Despite relatively longstanding connections, Japan's importance to Africa has slipped behind that of China, whose more aggressive approach has given it five times the trading volume and eight times the direct investment.

Beijing is criticised in some corners for what is sometimes seen as little more than a resources grab, and for not linking investment with demands for improved human rights or more transparent governance in recipient countries.

Japanese officials have stressed the need to transform their country's relationship with Africa from one of donor-recipient to that of business partnership, as Tokyo's firms seek to tap a burgeoning market.

Even so, Abe opened the TICAD on Saturday with a pledge of 1.4 trillion yen ($14 billion) in aid.

The cash, half of which was to be dedicated to spending on much-needed infrastructure projects, is included in 3.2 trillion yen that Japan's public and private sectors will invest in Africa over the next five years.

The package will include $1 billion aid to be spent on helping stabilise the Sahel region.

Japan is also aiming to double jobs offered by its firms in Africa to 400,000 by the next TICAD in 2018.

Africa's desperate need for roads, rails, ports and power grids dovetails well with Abe's pledge to treble the value of Japanese infrastructure exports to 30 trillion yen a year by 2020.

The continent's growing middle class also makes an attractive target for Japan's firms, whose domestic market is greying and shrinking.

Participants in the five-yearly TICAD on Monday issued the Yokohama Declaration, which picked up the theme of developing Africa's business potential and moving away from aid.

"We will encourage expanded trade, tourism and technology transfer, and assist the development" of small and mid-size local companies, it said.

"We will also support regional integration to expand intra-regional trade and create new opportunities for private-sector development and employment.

"Affirming that the private sector is a vital engine of growth, we will support and strengthen the private sector, promote greater private investment, and improve the investment climate and legal and regulatory frameworks."

Participants at the conference -- co-hosted by the African Union, the World Bank and the United Nations Development Programme -- said they want to improve production for farmers, who make up much of Africa's economy.

An "action plan" adopted Monday set goals of boosting growth in the agriculture sector by six percent and doubling rice production by 2018 compared to 2008 levels.

China said it hoped Japanese assistance would contribute to Africa's peace and development.

"We also hope Japan can follow through on various commitments it has made so as to deliver real benefits to African people," said foreign ministry spokesman Hong Lei in Beijing.

"China has provided selfless help to Africa for a long time and we will continue to do so."