An influential member of Prime Minister Benjamin Netanyahu’s coalition told settlers in the Israeli-occupied West Bank that the government is engaged in a stealthy effort to irreversibly change the way the territory is governed, to cement Israel’s control over it without being accused of formally annexing it.

In a taped recording of the speech, the official, Bezalel Smotrich, can be heard suggesting at a private event earlier this month that the goal was to prevent the West Bank from becoming part of a Palestinian state.

“I’m telling you, it’s mega-dramatic,” Mr. Smotrich told the settlers. “Such changes change a system’s DNA.”

While Mr. Smotrich’s opposition to ceding control over the West Bank is no secret, the Israeli government’s official position is that the West Bank’s status remains open to negotiations between Israeli and Palestinian leaders. Israel’s Supreme Court has ruled that Israel’s rule over the territory amounts to a temporary military occupation overseen by army generals, not a permanent civilian annexation administered by Israeli civil servants.

Mr. Smotrich’s June 9 speech at a West Bank gathering may make that posture harder to maintain. In it, he outlined a carefully orchestrated program to take authority over the West Bank out of the hands of the Israeli military and turn it over to civilians working for Mr. Smotrich in the defense ministry. Parts of the plan have already been incrementally introduced over the past 18 months, and some authorities have already been transferred to civilians.