Mr Eustice was responding to a parliamentary question from shadow Defra secretary Maria Eagle, who asked how the money would be saved.
Defra has been told by the Treasury to it must make £83m in "efficiency savings" in a government drive to reduce public spending by £3 billion during the current financial year.
Ms Eagle asked how the £83m reduction in spending would be met by Defra and the department's executive agencies and non-departmental public bodies.
Mr Eustice responded by saving Defra was planning to remain within its budgetary control totals for 2015-16 and is currently developing options to deliver the £83m savings.
He said: "These options include tight control of budgets to drive underspends in-year; further efficiency savings; and asset sales.
"The options are being considered across the core department and Defra's executive agencies and non-departmental public bodies."
Earlier, Mr Eustice said Defra hadn't reached any conclusions on how it would manage the budget it had been given – although all government departments were under pressure on spending.
But there was much more Defra could do when it came to managing its many agencies and arms-length bodes, Mr Eustice acknowledged.
"There is probably more scope for them to work more closely together or in partnership in certain areas where tasks overlap – and to find efficiency savings doing so.
"I certainly think there is scope given the number of arms length bodies we have."