Two Pacific island groups have declared states of emergency due to a severe lack of fresh water caused by a lingering drought.

The 1,400 residents of Tokelau, a territory of New Zealand, are down to a week-long supply of bottled water that was delivered last Saturday from Samoa. The independent nation of Tuvalu, meanwhile, has started rationing drinking water among its 11,000 citizens.

New Zealand sent a military cargo plane to Tuvalu filled with bottled water and desalination units, which turn salt water into fresh water. Tokelau is also seeking desalination units.

Tokelau and Tuvalu have gotten little to no rain for the past several months because of a weather pattern known as La Nina. The U.S. National Oceanic and Atmospheric Administration says La Nina is characterized by cooler than normal sea-surface temperatures in the central and eastern tropical Pacific, which affect global weather patterns.