Title: United States Secretary of Homeland Security
Content:  The United States secretary of homeland security is the head of the United States Department of Homeland Security, the federal department tasked with ensuring public safety in the United States. The secretary is a member of the Cabinet of the United States. The position was created by the Homeland Security Act following the attacks of September 11, 2001. The new department consisted primarily of components transferred from other Cabinet departments because of their role in homeland security, such as the Coast Guard, the Federal Protective Service, U.S. Customs and Border Protection (which includes the United States Border Patrol), U.S. Immigration and Customs Enforcement (which includes Homeland Security Investigations), the United States Secret Service and the Federal Emergency Management Agency. It does not, however, include the Federal Bureau of Investigation or the U.S. Marshals Service. They continue to operate under U.S. Department of Justice. The current secretary of homeland security is Alejandro Mayorkas, since February 2, 2021. He is the first Latino and immigrant to lead the Department of Homeland Security.
Title: 2019–2021 Department of Homeland Security appointment disputes
Content:  Kirstjen Nielsen served as the Senate-confirmed Secretary of Homeland Security from December 5, 2017 until April 10, 2019. On April 9, 2019, Nielsen had issued a new revision of Delegation 00106 that updated Annex A, but left Executive Order 13753 in place in the case of death, resignation, or inability. At the time, DHS referred to Annex A, which had Customs and Border Protection Commissioner Kevin McAleenan as next in line, rather than Executive Order 13753, which had Cybersecurity and Infrastructure Security Agency Director Christopher C. Krebs as next in line. While Nielsen demonstrably intended to place McAleenan next in line, and 
Title: Daniel W. Sutherland
Content:  Daniel W. Sutherland is the former Officer for Civil Rights and Civil Liberties at the U.S. Department of Homeland Security. He was appointed to the position on April 16, 2003 by George W. Bush and served until January 2009. Sutherland currently serves as the Associate General Counsel of the U.S. Department of Homeland Security, where he leads the National Protection and Programs Legal Division. His client, the National Protection and Programs Directorate, is responsible for cybersecurity, telecommunications, biometrics and infrastructure resilience. He oversees the provision of legal advice to the National Cybersecurity and Communications Integration Center (NCCIC), the largest cyber 
Title: Kirstjen Nielsen
Content:  On October 11, 2017, President Donald Trump nominated Nielsen to be the new United States secretary of homeland security, replacing acting secretary Elaine Duke. On December 5, 2017, the Senate confirmed her nomination, by a 62–37 vote. On December 6, 2017, she was sworn in as secretary of homeland security.
Title: United States Department of Homeland Security
Content:  The Department of Homeland Security is headed by the Secretary of Homeland Security with the assistance of the Deputy Secretary. The department contains the components listed below.
Title: Cabinet Office (Spain)
Content:  The Department of Homeland Security or Department of National Security, created in 2012 and regulated by the National Security Act of 2015, is the department of the Cabinet Office responsible for collecting and analysing information of interest for national security and advising the Prime Minister on such matters. The Director of the Department was, until 2018, the Deputy Chief of Staff of the Cabinet. The director is a member of the National Security Council along with the Chief of Staff. The headquarters of the department are located in the bunker of the Palace of Moncloa.
Title: John F. Kelly
Content:  On December 7, 2016, then President-elect Donald Trump nominated Kelly to head the Department of Homeland Security (DHS), a cabinet-level position. People familiar with the transition said that Trump's team was drawn to Kelly because of his southwest border expertise. On January 20, 2017, Kelly was confirmed as Secretary of Homeland Security by the United States Senate with a vote of 88–11. On that evening, he was sworn in by Vice President Mike Pence. In an April 2017 speech at George Washington University, Kelly said, "If lawmakers do not like the laws they've passed and we are charged to enforce, then they 
Title: United States Department of Homeland Security
Content:   In response to the September 11 attacks, President George W. Bush announced the establishment of the Office of Homeland Security (OHS) to coordinate "homeland security" efforts. The office was headed by former Pennsylvania Governor Tom Ridge, who assumed the title of Assistant to the President for Homeland Security. The official announcement states: "The mission of the Office will be to develop and coordinate the implementation of a comprehensive national strategy to secure the United States from terrorist threats or attacks. The Office will coordinate the executive branch's efforts to detect, prepare for, prevent, protect against, respond to, and recover from terrorist attacks within the United States." Ridge began his duties as OHS director on October 8, 2001. On November 25, 2002, the Homeland Security Act established the Department of Homeland Security to consolidate U.S. executive branch organizations related to "homeland security" into a single Cabinet agency. The Gilmore Commission, supported by much of Congress and John Bolton, helped further solidify need for the department. The DHS incorporated the following 22 agencies.
Title: Cabinet of Donald Trump
Content:  On December 7, 2016, John F. Kelly, retired four-star Marine general, was selected to be the Secretary of Homeland Security. He was confirmed by the Senate with a vote of88–11 and sworn in on the evening of January 20. Kelly's term ended on July 28, 2017, following his appointment as White House Chief of Staff.
Title: Elaine Duke
Content:  Elaine Costanzo Duke (born June 26, 1958) is an American civil servant and former United States Deputy Secretary of Homeland Security, serving from April 10, 2017 until April 15, 2018. She became acting Secretary of Homeland Security on July 31, 2017, when John F. Kelly assumed the office of White House Chief of Staff. She left the acting position on December 6, 2017, upon the confirmation of Kirstjen Nielsen.

Question: who is the head of the department of homeland security 2017?
Answer: Kirstjen Nielsen.