Israel has approved the acquisition of an aircraft to serve as an Air Force One-style transport for the prime minister, although details of the contract are veiled in secrecy.

A budget of about $100 million has been allocated for the acquisition of the undisclosed type and its conversion for the new role.

The budget approval is the first tangible sign of progress on the programme, which has been delayed by financial constraints and public criticism.

No details have been released on the identity of the company selected to perform the conversion, although work is scheduled to begin shortly.

Israel intends to use the new jet to replace an aircraft leased from flag carrier El Al.