What are the functions of the Head of Government in a presidential system?

In a presidential system the President is both Head of State and Head of Government. As Head of Government he performs the following functions:

1. Chief executive: He directs and controls the execution and enforcement of the laws of the state.
2. Formation of the cabinet: He appoints ministers and other principal officers and assigns portfolios to them.
3. Determination of policy: He formulates and directs the general policy of the government at home and abroad.
4. Commander-in-Chief: He is the head of the armed forces and is responsible for the defence and security of the nation.
5. Conduct of foreign affairs: He appoints and receives ambassadors, negotiates treaties and represents the country in international matters.
6. Assent to bills: He signs bills passed by the legislature into law and may veto bills he does not approve.
7. Prerogative of mercy: He grants pardon, reprieve or commutation of sentence to convicted persons.
8. Preparation of the budget: He presents the annual budget and appropriation proposals to the legislature.
9. Appointments: He appoints judges, ambassadors and heads of parastatals, often subject to legislative confirmation.