The drought-stricken Pacific island nation of Tuvalu is down to its last few days of water, prompting a mercy dash by New Zealand and Australia with water-making equipment.

Tuvalu, the world’s fourth-smallest nation sitting just below the Equator, has declared a state of emergency and is rationing water.

Tuvalu has a collective land mass of just 25 sq km (10 square miles) with its highest point five meters above sea level and is one of the countries most vulnerable to climate change and rising oceans.

Air force planes from New Zealand and Australia were combining on Friday to move a large desalination plant to Tuvalu, a group of small islands around 3,180 km (2,000 miles) northeast of New Zealand.

“The advice is that more capacity is needed to relieve the acute water shortage and replenish stocks,” said New Zealand Foreign Minister Murray McCully in a statement.