GENEVA -- France pledged Thursday that a controversial series of nuclear tests in the South Pacific would be its very last and said a test-ban treaty being negotiated in Geneva should cover absolutely all nuclear blasts.


France's commitments to the international Conference on Disarmament were welcomed by Australia -- which has led opposition to France's decision to resume testing -- and appeared to give a shot in the arm to a Comprehensive Test Ban Treaty, or CTBT.


France's ambassador to the conference, Gerard Errera, said President Jacques Chirac made it clear France supported the CTBT when he announced the resumption of testing.


"France is determined to spare no effort so that the aim of signing the Comprehensive Test Ban Treaty in the autumn of 1996 could be reached," Errera told the conference.


Errera then announced for the first time that Paris accepted an Australian formula that the treaty should "prohibit any nuclear weapon test explosion or any other nuclear explosion." This would include even the low-yield laboratory tests that Britain, Russia and the U.S. military want to continue.


Australian Foreign Affairs Minister Gareth Evans welcomed the news.


"If it's the case that the French are going to commit themselves [to a regime] with a zero threshold, then that is a really major and significant step forward in nuclear policy," Evans said.


But environmentalists at Greenpeace were skeptical and said France was still hanging on to an "opt-out clause."