"The time has come for the international community to recognize reality, especially two basic facts," said Benjamin Netanyahu during a Cabinet meeting Sunday.
"One, whatever is beyond the border, the boundary itself will not change. Two, after 50 years, the time has come for the international community to finally recognize that the Golan Heights will remain under Israel's sovereignty permanently."
Israel seized parts of the Golan Heights, a strategic, rocky plateau to its northeast, from Syria in the 1967 Six Day War.
Syria unsuccessfully attempted to retake it during the 1973 Yom Kippur War, before Israel annexed the region in 1981 by extending its laws over the territory and its occupants.
The international community considers the Golan Heights to be occupied territory, and Israeli settlement-building there to be illegal.
Syria wants the return of the territory, which has been monitored by U.N. peacekeeping forces for decades.
'Integral part' of Israel
Netanyahu said the presence of ancient synagogues in the Golan Heights showed that the territory, with a population of about 50,000, had been "an integral part of the Land of Israel since ancient times," and that it remained an integral part of modern Israel.
"During the 19 years that the Golan Heights were under Syrian occupation, when they were a place for bunkers, wire fences, mines and aggression, they were for war. In the 49 years that the Golan Heights have been under Israeli rule, they have been for agriculture, tourism, economic initiatives and building. They are for peace," he said.
"In the stormy region around us, Israel is the stabilizing factor; Israel is the solution, not the problem."
Netanyahu said he had spoken Saturday night with U.S. Secretary of State John Kerry, and told him that he doubted that war-torn Syria would ever revert to its pre-war state.
He said the Syrian state had "persecuted minorities, such as the Christians, Druze and Kurds, who are justly fighting for their future and their security," while the chaos of the conflict had allowed "terrorist elements, especially Daesh (another name for ISIS), Iran and Hezbollah" to flourish across the border.
Those factors highlighted the need for the area -- which, beyond its military significance is an important source of water and fertile land -- to remain under Israeli control.
"The Golan Heights will forever remain in Israel's hands," the Prime Minister said. "Israel will never come down from the Golan Heights."
Syria appeals to U.N.
Syria responded angrily to the Cabinet meeting, with state-run SANA news agency reporting that Damascus had sent letters to U.N. Secretary-General Ban Ki-moon and to the head of the U.N. Security Council condemning "in the strongest of terms the holding of a provocative meeting in the occupied Syrian Golan."
The letters called on the United Nations to intervene to ensure the meeting was not repeated, SANA reported.
The agency also ran a statement saying that the "people of the occupied Syrian Golan emphasized that the Golan has always been and will forever be part of the Syrian land and that this truth is firm no matter how the Israeli occupation authorities try to show otherwise."
Buffer against Syrian fighting
Weapons fire from Syria has intermittently struck the Israeli-controlled Golan Heights as the country's five-year civil war rages.
In comments made to Israeli forces in the Golan Heights last Monday, Netanyahu said Israel had conducted "dozens" of attacks across the Syrian border.
"We operate when we need to operate, including across the border in dozens of attacks to prevent Hezbollah from acquiring weapons that break the balance," he said in a video released by his office. "We operate also in other theaters near and far."
The admission that Israel conducts strikes in Syria was significant, since no Israeli leader has ever openly acknowledged Israel's operations in Syria. It comes as world leaders are trying to negotiate an end to the civil war in that country.