China's launch of a biodiversity fund is a "good start" but falls short of what is needed to help developing countries meet the goals in a global nature pact, environmentalists have warned, urging all rich nations to step up ambition and funding.

About 195 countries are set to finalize a new accord to safeguard the planet's plants, animals and ecosystems at a two-part U.N. summit that began this week and is due to finish in May next year in the Chinese city of Kunming.

Addressing the COP15 biodiversity virtual summit on Tuesday, Chinese President Xi Jinping announced the highly anticipated launch of a 1.5 billion yuan ($232.47 million) fund to support biodiversity protection in developing countries.