CANBERRA - President Tony Tan Keng Yam kicked off a six-day state visit to Australia on Sunday with a tree-planting ceremony at the National Arboretum here.

Accompanied by his wife Mary, Dr Tan shoveled soil and poured water over a pink silk tree, specially chosen as its flowers are similar to those of Singapore's native rain tree.

Speaking before the ceremony began, Chief Minister of the Australian Capital Territory Katy Gallagher, who had called on Dr Tan earlier in the afternoon, said the two had discussed the friendship between both countries.

"And what greater way to symbolise that than a planting of a tree forever to remind visitors at the National Arboretum just how important that friendship is," said Ms Gallagher.

The National Arboretum houses some 48,000 symbolic, rare and endangered trees from Australia and around the world that have been planted for scientific, conservation, educational and research purposes. It was officially opened last year.

Earlier in the day, President Tan was welcomed on arrival at the Royal Australian Air Force Fairbairn airbase by Mr Philip Green, Australia's High Commissioner to Singapore, and representatives from the Australian Governor-General's Office and the Department of the Prime Minister.

On Monday, he will be hosted to a state lunch by Governor-General Sir Peter Cosgrove and lay a wreath at the Australian War Memorial.