"[We] invite all relevant international institutions and aid and development agencies to make it a priority to develop and implement policies which promote ecologically sustainable livelihoods for local and indigenous communities and which prevent actions and activities that are detrimental to the survival of great apes populations," they said in a statement.
The statement, made in Kinshasa, capital of the Democratic Republic of Congo, at the end of their conference, also called for national plans to "halt and reverse the decline of great ape populations, while ensuring the participation of the relevant parties involved, in particular local communities".
The numbers of gorillas, chimpanzees, bonobos and orang-utans have been devastated by poaching for bush-meat, trafficking in live animals, exploitation of forests and rapidly-growing human populations to the point where they face extinction.
Conference participants were told the apes would be gone in 50 years unless rapid action was taken to protect the dense, wet forests in which they live.
Great apes have been decimated
by poaching and habitat loss
"[We] encourage the provision of long-term ecologically sustainable direct and indirect economic benefits to local communities, for example, through the introduction or extension of carefully regulated sustainable eco-tourism in areas of great apes habitat, and the creation of long-term research projects operating in or near these areas," the final declaration said.
The representatives also called for "the development and implementation of national great apes survival plans and other appropriate actions by [great ape] range states in the implementation of their great apes survival plans and any other appropriate action".
Belgium, the European Union, France, Japan and the US promised at the conference to continue and intensify their participation in protection programmes.
The 150 conference participants also called for more cooperation between states in enforcing legislation protecting the apes.
The statement reaffirmed the representatives' "commitment to work together to ensure that the Great Apes Survival Project Partnership (Grasp) has the capacity to realise its full potential as a key component of the international effort to save great apes".
The Democratic Republic of Congo, home to three of the world's four great apes species, called for more money from developed countries to save the animals from extinction.
"Whether it be for research or for action on the ground, we need money"
Congo's environment minister
"Whether it be for research or for action on the ground, we need money. It is poverty in the first place that leads to poaching," the country's Environment Minister Henri Dojombo told the international conference.
"In central Africa, we have promoted a programme in protection and sustainable management of the forest, the habitat of the great apes," he said.
"This plan, costing $2 billion for 11 countries over five years, suffers from a lack of funding," he added.
The vast central African nation of 58 million people is home to gorillas, chimpanzees and pygmy chimpanzees called bonobos.
Conservationists say the bonobos population alone has collapsed from about 100,000 to 10,000 in the past 15 years.
A decade of civil war saw the apes' forest habitat decimated by illegal mining and logging, and taken over by refugees fleeing conflict in the volatile Great Lakes region.
Despite the armed forces taking control of the forests, poaching of the animals continues unchecked, say wildlife experts.