Washington, Jan 12 : US Acting Secretary of Homeland Security Chad Wolf has resigned from his post, making him the third cabinet member of outgoing President Donald Trump's administration to leave office following the January 6 storming of the Capitol building. The Senate had not approved Wolf's nomination since Trump tapped him to lead the Department of Homeland Security (DHS) in November 2019, confining him in an Acting role heading the department for 14 months, Xinhua news agency reported. In a letter to the DHS on Monday night, Wolf said ithat his resignation "is warranted by recent events, including the ongoing and meritless court rulings regarding the validity of my authority as Acting Secretary". "These events and concerns increasingly serve to divert attention and resources away from the important work of the Department in this critical time of a transition of power," said Wolf, whose resignation became effective just before midnight. Wolf's tenure has been marked by controversies over the legality of the appointment and his implementation of the Trump administration's immigration policies. A federal judge in Maryland ruled in September 2020 that Wolf was likely unlawfully serving as acting DHS secretary, since his predecessor, Kevin McAleenan, possibly violated the proper order of succession in appointing him. That ruling was agreed by another federal judge in New York in November which, by that reason, blocked Wolf's attempt to suspend the protection for child immigrants brought to the US known as "Dreamers". Referring to the resignation, Wolf said he was "saddened to take this step, as it was my intention to serve the Department until the end of this administration". Wolf said in the letter that he will be replaced by the head of the Federal Emergency Management Agency, Pete Gaynor, who will also serve in an acting capacity. Wolf's resignation came as the fallout of pro-Trump demonstrators' breach of the Capitol Hill compelled a growing number of administration officials to resign. He was the third cabinet member to step down, following Transportation Secretary Elaine Chao and Education Secretary Betsy DeVos. Wolf did not directly mention the Capitol siege in his resignation letter, but he condemned the rioters for their "unconscionable" violence, one day after they stormed the Capitol building to disrupt Congress's certification of the 2020 presidential election results. While explicitly calling Trump supporters' acts "unacceptable", Wolf said then that he intended to remain in his post. As Wolf's successor, Gaynor is now in charge of overseeing federal and state security preparations for the inauguration of President-elect Joe Biden on January 20. The Federal Bureau of Investigation has warned about planned protests across state capitals and Washington, D.C., in the lead-up to the event. /IANS