Australia has sent a delegation to Papua New Guinea to complain about a planned mine along the Kokoda Track, where hundreds of Australian soldiers died fighting Japanese forces in the Second World War.
Australia's Prime Minister, John Howard, says he has sent senior officials to convey Canberra's concern about the gold and copper mine planned by Australian miner Frontier Resources Ltd.
Mr Howard says Australia respects the laws of Papua New Guinea, but the Kokoda Trail is of enormous historic and military significance to Australia.
Australia is already fending off accusations of diplomatic bullying from another neighbour after Solomon Islands expelled Canberra's top diplomat in Honiara this month, accusing him of undermining an inquiry into April riots.
The Kokoda Track, running 96 km through PNG's rugged Owen Stanley Ranges, has become a place of modern pilgrimage for thousands of Australians who walk it each year.
Australian soldiers, assisted by PNG tribesmen, fought in atrocious conditions and against vastly superior numbers on the track between July 1942 and January 1943, inflicting the first land defeat on the Japanese.