Australian Environment Minister Peter Garrett says Australia will try to convince like-minded countries to reject a compromise deal that will allow limited commercial whaling.
Members of the International Whaling Commision are meeting in Morocco this week on a proposal to change a ban on the commercial killing of whales. The ban has been in place for the 24 years.
Japan, Norway and Iceland have continued to kill whales.
The proposed changes are aimed at coaxing these countries back into the IWC mainstream - by providing a quota that would be subject to independent scrutiny.
However, Mr Garrett says any proposal to allow whaling will be vigorously resisted.
The IWC has 88 members.
Foreign Affairs Minister Murray McCully and New Zealand's IWC representative, Sir Geoffrey Palmer, will share the leadership of the New Zealand delegation for the final days of the meeting.
Officials from the Ministry of Foreign Affairs & Trade and the Department of Conservation will also attend.
So will Greenpeace, which says IWC chairman Cristian Maquieira has withdrawn from the meeting due to ill health. It fears the talks may stall without his involvement.
The lobby group says an enormous amount of political will is needed for the negotiations to reach an agreement.