SYDNEY, May 13 (Reuters) - Australia will forecast a budget surplus of A$9.3 billion ($6.13 billion) for the fiscal year ending June 2024 thanks to a strong labour market and high commodity prices, marking the first back-to-back surpluses in nearly two decades.

Treasury said late on Monday that is an improvement of A$10.5 billion from the Labor government's mid-year economic and fiscal outlook in December, which tipped a small deficit of A$1.1 billion.

That compared with a surplus of A$22.1 billion for the 2022-23 fiscal year, the first surplus in 15 years.

Treasurer Jim Chalmers will announce the government's budget for the 2023-24 fiscal year on Tuesday.

($1 = 1.5161 Australian dollars) (Reporting by Stella Qiu; Editing by Sam Holmes)