An entire senior management team of the US State Deparment has resigned under the new adminstration of President Donald Trump, local media has reported.Four leading US officials from the State Department, which advises the US president and leads the country in foreign policy issues, left their posts on Wednesday, but the reason for the walkout has not been confirmed, the Washington Post said.Patrick Kennedy, the department`s undersecretary for management; Joyce Anne Barr, assistant secretary of state for administration; Michele Bond, the assistant secretary of state for consular affairs; and Gentry Smith, director of the office of foreign missions, resigned unexpectedly, the US newspaper reported on Thursday.According to the Reuters news agency, Undersecretary of State for Arms Control and International Security Thomas Countryman will also leave his post by Friday.Turnover is the rule, rather than the exception, among the top officials in the US government when the White House changes hands from one party to another, in this case from Democrat Barack Obama to Republican Donald Trump.A week ago, Trump`s nominee for Secretary of State, former Exxon Mobil Corp chairman Rex Tillerson, was confirmed by the Senate foreign relations committee. He has yet to be confirmed by the full Senate.In a separate development, the US Border Patrol Chief Mark Morgan, a former longtime FBI agent, has left the agency, a source familiar with his departure told the Reuters news agency on Thursday. The reason for his departure was not immediately clear.The resignations came soon after Trump signed an order for a controversial wall on the border with Mexico. He has also in his first week of office signed orders restricting visas and immigration from countries including Somalia, Sudan, Iran, Yemen and Iraq, and the entry of refugees.Source: News agencies