I want to know the answer to the following question:
What organization called for Tuvalu to  improve its water and sanitation systems?
All the background I'm provided with is that "In 2012, Tuvalu developed a National Water Resources Policy under the Integrated Water Resource Management (IWRM) Project and the Pacific Adaptation to Climate Change (PACC) Project, which are sponsored by the Global Environment Fund/SOPAC.". Is that enough to answer the question?
Answer: no