Israel’s hardline foreign minister says there will be a tough response if the Palestinians follow through on a plan to declare independence at the United Nations this fall.

Avigdor Lieberman told reporters on Wednesday that “unilateral steps will force us to take unilateral steps.”

He says Israel is considering a variety of responses but declined to elaborate.

Lieberman has earlier suggested that Israel could annul past peace agreements or annex parts of the West Bank.

With peace talks deadlocked for more than two years, the Palestinians plan to ask the U.N. to recognize their independence in September.

The move would be largely symbolic but the Palestinians hope it will pressure Israel to withdraw from captured territories they claim for a future state.