Interviewed on Channel 10 TV on Monday in the wake of the eviction of settlers from 21 colonies in the Gaza Strip and four in the West Bank, Sharon said it was likely more land would have to be returned to Palestinians.
"Not all the settlements of today in Judea and Samaria [the occupied West Bank] will remain," he said.
But the premier insisted all major settlement blocs would remain under Israeli sovereignty - adding there would be no "second stage of disengagement," as he calls the pullout, either unilateral or coordinated.
He said the next step must be negotiations under the "road map" peace plan that leads through three stages to a Palestinian state.
Sharon said the issue of Israel's borders could be raised only at the end of the blueprint. The final version of the road map will be determined in the last stage of the process.
Sharon blasted his party rival, Benjamin Netanyahu, who is expected to announce his candidacy this week to challenge Sharon for leadership of the Likud party.
Netanyahu resigned as finance minister days before the Gaza Strip pullout, saying he could not take responsibility for it.
Benjamin Netanyahu quit his post
as finance minister
This coincided with presentation of next year's budget to the Cabinet.
On both counts, Sharon said Netanyahu displayed irresponsibility. "He panics and loses control. I've seen that more than once," Sharon said.
"Someone who runs from responsibility ... cannot be trusted to run the country, certainly not a country like Israel," he said.