WELLINGTON, June 5 (Xinhua) -- The New Zealand government's surplus, revenue, expenses and net debt are all tracking in line with forecasts, according to the latest monthly financial accounts released by the Treasury on Tuesday.

"The surplus in the 10 months to the end of April was slightly higher than expected," Finance Minister Grant Robertson said in a statement.

The Treasury reports that the operating balance before gains and losses (OBEGAL) was a surplus of 3.4 billion NZ dollars (2.4 billion U.S. dollars) on April 30, which was 159 million NZ dollars higher than forecast, Robertson said.

"The Budget Responsibility Rules require us to run surpluses to ensure that we have money set aside for a rainy day," he said.

"This gives us the ability to respond to shocks like the cattle disease Mycoplasma bovis, where Cabinet was able to agree to stand alongside industry for our one shot at eradication because we have ensured the government is in a strong fiscal position," Robertson said.

Tuesday's financial accounts show net debt at 22.1 percent of GDP, exactly in line with the budget forecast, the minister said.

"It is good to see these actual results indicate that business profit growth is tracking as expected, and that businesses are continuing to hire new workers as the economy continues to grow," he said, adding the Treasury is forecasting annual economic growth averaging at about 3 percent a year over the next four years.