Three hundred not-for-profit groups joined forces last week with 22 governments from around the world, including the UK, to launch an international campaign on animal welfare.
They became the first signatories of a Declaration on Animal Welfare, which contains principles that they hope will become enshrined in international law.
They pledged support at a conference in the Philippines that was sponsored by the World Society for the Protection of Animals (WSPA) and the RSPCA.
The League Against Cruel Sports, the Donkey Sanctuary and the National Animal Welfare Trust were among the other UK-based signatories.
Peter Davies, director-general of WSPA, hailed the declaration as "a historic and landmark agreement".
"Government delegations have, for the first time at an international conference, recognised the importance of animal welfare and their responsibility in developing humane standards," he said.
The first principle states "the welfare of animals shall be a common objective for all nations". Others call for "all appropriate steps" to be taken to prevent cruelty.