Japan said Thursday it has made no agreement to stop hunting humpback whales, denying comments from the US ambassador here that suggested a temporary deal had been struck. "There is no (new) written, diplomatic agreement between Japan and the United States over the current specific whaling mission... and whaling in general," said Tomohiko Taniguchi, spokesman for the Japanese foreign ministry.He was responding to comments by US ambassador Thomas Schieffer, who reportedly told journalists Wednesday that Japan and the United States agreed on no harvesting of humpback whales for the time being.Taniguchi said the ambassador might have meant to refer to various discussions between Japan and the United States and suggested whaling had been one of many topics covered.He added, however, that he was not aware of the context in which Schieffer made the remarks."I cannot disclose exactly what diplomatic discussions we are having. But there is no concrete, diplomatic agreement on whaling between Japan and the United States," Taniguchi said.Japan's ships set sail last month on the country's largest hunt yet, which for the first time since the 1960s will kill humpbacks, one of the most popular animals for Australian whale watchers.The mission defied warnings from Japan's usual Western allies including Australia.Australia's new left-leaning government said Wednesday it would deploy an unarmed customs ship and a surveillance aircraft to monitor the Japanese hunt as well as appoint an envoy in Tokyo to press its case.Tokyo responded on Wednesday, calling for calm and voiced hope Australia would come to understand its whaling.Japan, which says whaling is part of its culture, is carrying out the hunt in the Antarctic Ocean using a loophole in a 1986 global moratorium on commercial whaling that allows "lethal research" on the giant mammals.Meanwhile, Greenpeace on Thursday called on new Australian Prime Minister Kevin Rudd to contact his Japanese counterpart Yasuo Fukuda and demand a halt to whaling in waters off Antarctica.Greenpeace's Australia Pacific chief Steve Shallhorn said Rudd, who made campaign pledges to keep Australia strongly opposed to whaling before his centre-left Labor Party won power last month, needed to become personally involved in the issue."There's still time, this issue is developing, and I think it's appropriate for the Australian prime minister to pick up the phone and talk to the Japanese prime minister," he told reporters.Shallhorn, however, welcomed Australia's plan, announced Wednesday, to send an unarmed customs vessel and an aircraft to the Southern Ocean to monitor the Japanese whaling fleet and step up diplomatic efforts to end the cull.Shallhorn also claimed Japan was planning to build a new whaling factory ship with the capacity to double the nation's whale kill.The existing whaler "Nisshin Maru" was temporarily disabled in a fire that killed a crew member earlier this year and Shallhorn said a Japanese fisheries industry newspaper had reported a new vessel was being considered last May.