There's been a $1.1b increase in tourist spending in the past year.

The growth is contributed to increasing numbers of visitors from the United States and China.

Total tourism expenditure has increased 5% to $23.8b.

Spending by international tourists increased 7.4% - or $709m.

That follows a slight decrease in the previous year.

The increase in spending by international visitors is the largest since 2002.

Overall, tourism directly contributed to 4% of Gross Domestic Product.