Global food security starts with ensuring access to water, the head of the Food and Agriculture Organisation (FAO) said at the beginning of World Water Week Monday.

"There is no food security without water security," said FAO director-general Jose Graziano Da Silva in Sweden, which is hosting the annual event organised by the Stockholm International Water Institute (SIWI).

With crop growing hampered by the effects of pollution and climate change, agriculture must become "more efficient and fairer", he said, adding that nations all over the world need to "produce more with less" and manage water resources well.

The conference, whose theme is water and food security, also heard from Swedish Cooperation Minister Gunilla Carlsson who urged the business world to find fresh ideas and new partners to help improve food security.

"The need for innovation and collaboration with corporations and small businesses are significant," she said.

"Increasingly, business is looking for innovative models building on local ideas and demand, rather than adapting products and distribution processes that were conceived for US or European markets."

Da Silva also called on the private sector to develop agriculture in a responsible manner in emerging countries.