His promise on Monday comes before a trip to Washington to secure US approval for his plans for a unilateral Gaza pullout.
"Only Israeli political initiative will retain our strong grasp of the large settlement blocs and security areas," Sharon said at Israel's largest West Bank settlement, Maale Adumim.
"[These are] places that will remain under Israeli control that will continue to grow stronger and develop," he said.
Sharon named several West Bank settlements that would remain under Israeli control, including Maale Adumim, Ariel, Givat Zeev, and the town of Hebron, which Israel and the Palestinians control different parts of.
He told the settlers their homes would "continue to be built as part of Israel, for all eternity", and urged them to accept his plan to unilaterally withdraw from all settlements in the Gaza Strip and a few from the West Bank.
Sharon flies to Washington later for a White House meeting with US President George Bush at which Israeli sources said they expected a deal ensuring Israel would not have to cede all of the West Bank in any future peace deal with the Palestinians.
Closed the door
Palestinian chief negotiator Saib Uraiqat has condemned Sharon's pledge, saying it closed the door on a peace deal between Israel and the Palestinians.
"With this statement, Sharon is closing the door before any Palestinian-Israeli peace deal," Uraiqat said. "The withdrawal from Gaza cannot be exchanged for maintaining Israeli occupation in Jerusalem or in the West bank."
While polls have indicated that most Israelis support Sharon's plan, Jewish settlers, marching along a main Israeli highway and inside Maale Adumim while Sharon spoke, protested against a Gaza pullout, calling it a "victory for terror".
Sharon says the pullback would enable Israel to "disengage" from the Palestinians after more than three years of violence while drawing a security line in the West Bank that would leave them with less land than they seek for a state of their own.
Palestinians want a state on territories seized by Israel in the 1967 Middle East war and fear that Israel will give up the Gaza Strip just to consolidate its grip on far larger West Bank settlements.
Sharon told the settlers Palestinians have failed to stop attacks against Israelis, saying: "As long as they understand this [withdrawal] marks an end to their dreams for years ... it's possible they will decide to take the necessary steps."