The Defence Secretary as head of the Department of Defence, is the senior most civil servant in the ministry and is responsible for coordinating the activities of the four departments in the ministry. His or her role is to ensure that the MoD operates effectively as a department of the government. Defence Secretary is assisted by additional secretaries and joint secretaries to Government of India posted in the ministry. The Defence Secretary, generally is an officer from the Indian Administrative Service, apart from the Defence Secretary, there are three other secretary-level posts in the Ministry of Defence.