Shaul Mofaz was quoted by public radio on Sunday as telling the weekly cabinet meeting that "the security conditions are not ready for these convoys at the moment".
The convoys across Israel should have begun operating last Thursday under the terms of the agreement overseen by Condoleezza Rice, the US secretary of state, that also led to the opening of the Rafah border crossing between Egypt and Gaza.
However, Israel decided to freeze all talks on the link after a bombing in the coastal city of Netanya that killed five Israelis. It accused the Palestinian Authority of doing nothing to rein in militant groups.
The US is understood to have placed heavy pressure on Israel to allow the bus convoys as soon as possible.
Under the terms of the agreement, Israel should also allow convoys of trucks to travel between the Gaza Strip and the West Bank from 15 January.
Since Israel withdrew from Gaza over the summer, the Palestinians have said that their territory will become a "giant prison" if its residents are not allowed regular access to the occupied West Bank.