Israel’s government has taken unilateral steps to give itself greater control over the occupied West Bank, challenging President Trump’s opposition to Israeli annexation of the territory in a move widely considered a violation of international law.

The measures, which make it easier for Jewish settlers to buy land and undercut the Palestinian Authority in parts of the West Bank that it administers, appear to flout important agreements that Israel signed under the Oslo peace process decades ago.

The changes were made by Prime Minister Benjamin Netanyahu’s security cabinet at a closed-door meeting on Sunday. By enhancing Israel’s control over West Bank territory the Palestinians want for a future state, they effectively advance the cause of annexation by degrees — continuing a strategy that the government has been pursuing for years.

But they come after Mr. Trump’s recent, explicit rejection of annexation, his acknowledgment of the Palestinians’ aspirations to statehood — made explicit in his peace plan for Gaza — and his support for political talks between the Israelis and Palestinians.

Mr. Netanyahu, who is set to travel to Washington to meet with Mr. Trump on Wednesday, did not announce the changes. Instead, they were detailed after Sunday’s meeting by two government ministers who oversee West Bank policy.

One was Bezalel Smotrich, the far-right finance minister, who has pushed through a host of other measures extending Israel’s footprint in the West Bank.