Israel has never declared it's borders. Infact, it has been appropriating Palestinian land since it's creation in 1948.
By way of illegal settlements, seperation walls and 'closed military zones', upto 10% of the remaining Palestinian Territories now fall under Israeli jurisdiction, despite this being illegal under International Law.
Palestininan's have conceded upto 78% of Historical Palestine to the Jewish State. The ongoing illegal appropriation of Palestininan land by Israel is one of the core drivers that ensures peace remains elusive.
Israel's policy has been to annex as much land as possible, before it is forced to stop.