SYDNEY (REUTERS) - Australian Deputy Prime Minister Barnaby Joyce has tested positive for Covid-19 in Washington while on an official visit, his office said in a statement on Thursday (Dec 9).

The remaining members of his delegation have tested negative and Mr Joyce will remain in isolation until further advice, the statement said.

Mr Joyce had been experiencing mild symptoms and chose to get tested for Covid-19. He is the highest-ranking Australian leader to contract the virus since the pandemic began.

Mr Joyce reached the United States on Tuesday after a visit to Britain, where he met senior government officials.

Separately, Australia's Queensland state has fully vaccinated 80 per cent of its population that are eligible for the Covid-19 jab, a key threshold to reopen its borders with the nation's two biggest states, New South Wales and Victoria.

The state will reopen to fully vaccinated travellers from New South Wales, Victoria and the Australian Capital Territory from Monday.