Under Article 20 of the Constitution of Bhutan, executive power is vested in the Lhengye Zhungtshog, consisting of the Ministers headed by the Prime Minister. The number of Ministers is determined by the number of Ministries required to provide efficient and good governance. Creation of an additional ministry or reduction of any ministry must be approved by Parliament. The Lhengye Zhungtshog must aid and advise the King in the exercise of His functions including international affairs, provided that the King may require the Lhengye Zhungtshog to reconsider such advice. The Prime Minister must keep the King informed from time to time about the affairs of the State, including international affairs, and must submit such information and files as called for by the King.