New Zealand and the United States have joined to help get fresh water to the tiny drought- stricken Pacific island nation of Tokelau, the New Zealand government announced Wednesday.

A Royal New Zealand Air Force Hercules would Thursday carry supplies including 12 large, empty military water storage containers and personnel to Pago Pago, American Samoa, said New Zealand Foreign Minister Murray McCully.

In Pago Pago, the New Zealand team would link up with U.S. Coastguard cutter Walnut, which had an on-board water desalination plant that had filled its water tanks, providing about 136,000 litres of water.

The Walnut would travel to Tokelau's three main atolls with enough water, according to New Zealand estimates, for a " sufficient supply in the short term."

"A severe La Nina weather pattern is operating in the Pacific region resulting in very low rainfall for many areas," said MrCully.

The New Zealand Red Cross Tuesday described the severe drought in Tuvalu and Tokelau as "grim" and likely to get worse.

Neither country has seen any significant rainfall for the last six months and none is expected for another two months.

Both countries have declared states of emergency and water rationing has reached critical levels.

Tuvalu has a population of about 12,000 people, who live across nine atolls with a total land area of about 27 square kilometers.

Tokelau comprises three atolls located about 483 km north of Samoa. The atolls are 3 to 5 meters above sea level.