The Tuvalu opposition says the government will support Japan's call to lift a 20-year moratorium on whaling.
Tuvalu is a member of the International Whaling Commission that will have its main meeting in South Korea next week.
IWC members are expected to vote on whether to let Japan double the number of minke whales it kills each year, and to resume hunting other species like humpbacks.
An Opposition MP in Tuvalu, Apisai Ielemia, says the government's decision was a big surprise for many because traditionally whales are sacred.
"They probably had their arms twisted. Tuvalu has its own way of voting in accordance with what is good for Tuvalu. And for this issue it was a big surprise to us that the answer from the government was in favour."
Apisai Ielemia, an opposition MP in Tuvalu