Melbourne, Apr. 4 : Australian Prime Minister Kevin Rudd has been caught on film saluting U. S. President George W. Bush, but he says the incident was just a joke.

Cameras caught the gesture as world leaders gathered in Bucharest for talks on NATO's involvement in Afghanistan.

In the film, Rudd is seen saluting the President in acknowledgment, bringing to mind Bush's description of former prime minister John Howard as his "deputy sheriff".

But asked about the moment later, Mr Rudd laughed out loud and said it was "a joke".

The Prime Minister will leave Bucharest with Australia's demands for NATO troops to carry a bigger burden in Afghanistan partially satisfied.

But his plan for the destruction of drug crops failed to win support.

He again reaffirmed Australia's commitment to staying in Afghanistan for the "long haul" but said its support wasn't a "blank cheque".

Australia, which has 1000 troops in the southern province of Oruzgan, has repeatedly called for greater burden sharing by NATO allies, particularly the Europeans. (ANI)