The Pacific island nation of Tuvalu has declared a state of emergency due to a severe shortage of freshwater,
with officials saying that some parts of the country may only have a two-day supply.
Murray McCully, New Zealand's foreign minister, said on Monday that water was scarce in the capital, Funafuti, and a number of outlying islands.
New Zealand was working with the Red Cross to deliver aid workers and supplies as quickly as possible, he added.
"A New Zealand Defence Force C-130 left this morning to take supplies and personnel to Tuvalu," he said in a statement. "The supplies include two desalination units as well as water containers.
"New Zealand will be working with partners and other donors to consider the best medium-to-long-term response options".
Tuvalu first declared the emergency last week and the situation has deteriorated since then.
A Red Cross report released last week said the nation - a grouping of low-lying coral atolls that is home to less than 11,000 people - relied mostly on rainwater, with some islands having access to ground water.
Rain fall has been scarce in the last six months because of a weather pattern known as "La Nina" across the Pacific.
The Red Cross reported an especially critical situation on the island of Nukulaelae, south of Funafuti, where most of the population was being rationed to 40 litres of water per family per day.
The former British colony is not the only Pacific island running out of drinking water. Officials from Australia and New Zealand have said they are worried about other islands in the region, including Tokelau.