Washington ( CNN ) -- Homeland Security Secretary Janet Napolitano announced Friday she is resigning and will be nominated to become president of the University of California system . In an e-mail to associates , Napolitano said she will leave the Department of Homeland Security in September . While her nomination must be approved by the university 's board of regents at a meeting next week , Napolitano sounded confident of the outcome . `` Departing a job and community you love is never easy , but I am passionate about educating the next generation of leaders and the University of California is like no other institution in affording such an opportunity , '' her e-mail said . She graduated from the University of Santa Clara in California in 1979 as its first female valedictorian . Napolitano , 55 , was confirmed as the nation 's third homeland security secretary and the first woman to hold the post the day after President Barack Obama took office in 2009 . Janet Napolitano : Fast Facts . In an earlier statement on Friday , she called working with homeland security personnel who protect the nation `` the highlight of my professional career . '' Obama thanked Napolitano for what he called outstanding work in dealing with `` some of the toughest challenges facing our country . '' He cited her leadership in recovery efforts from natural disasters like Superstorm Sandy , dealing with the volatile immigration issue and protecting the nation against terrorist attacks . `` I 've come to rely on Janet 's judgment and advice , but I 've also come to value her friendship , '' Obama said , wishing her luck `` as she begins a new chapter in a remarkable career of public service . '' A breast cancer survivor , Napolitano was attorney general and then governor of Arizona before joining Obama 's Cabinet . As head of the vast department involved in all aspects of national security including anti-terrorism efforts , Napolitano was involved in some of the most high-profile moments of Obama 's first term . She was criticized for defending screening efforts after the 2009 attempted terrorist attack in which a man on a flight from Europe failed to ignite explosives in his underwear . During her tenure , the administration deported record numbers of undocumented immigrants . However , GOP critics complained Napolitano ignored the law by halting deportations of some young immigrants living illegally in the United States as part of administration reforms of the broken immigration system . Some officials at the Immigration and Customs Enforcement agency complained that the policy change forced agents to violate laws . Conservative Republican Sen. Jeff Sessions of Alabama said Napolitano 's tenure `` was defined by a consistent disrespect for the rule of law . '' `` Any selection -- interim or permanent -- to replace Secretary Napolitano must disavow these aggressive non-enforcement directives or there is very little hope for successful immigration reform , '' Sessions said in a statement . Other legislators called for Obama to swiftly name a replacement . Names previously mentioned as possible successors include New York City Police Commissioner Raymond Kelly and retired U.S. Coast Guard Adm. Thad Allen , the service 's former commandant . The Homeland Security Department was created in the aftermath of the September 11 , 2001 , terrorist attacks on New York and Washington . Former Pennsylvania Gov . Tom Ridge was the first secretary , followed by Michael Chertoff , both during the administration of GOP President George W. Bush . In a statement Friday , Kelly and New York Mayor Michael Bloomberg praised Napolitano for prioritizing federal funding for the city 's anti-terrorism programs during an era of budget austerity . `` Secretary Napolitano never lost sight of the fact that New York City was on the top of the terrorist target list and acted accordingly in funding important initiatives , '' Kelly 's statement said . `` She performed a great public service not only for New York City but for the nation at large . '' At the University of California , Napolitano will lead a system with more than 234,000 students at 10 campuses , five medical centers and three affiliated national laboratories . Sherry Lansing , the former film studio executive who headed the search committee , said Napolitano received unanimous support from the nominating panel . `` While some may consider her to be an unconventional choice , Secretary Napolitano is without a doubt the right person at the right time '' to lead the university , Lansing said in a statement . `` She will stand as a vigorous advocate for faculty , students and staff at a time when great changes in our state , and across the globe , are presenting as many opportunities as challenges . '' CNN 's Gabriella Schwarz , Deirdre Walsh , Greg Seaby and Carol Cratty contributed to this report .
NEW : GOP critics say Napolitano ignored laws regarding undocumented immigrants . Janet Napolitano says she will leave the Cabinet in September . Comment: She will be nominated to be president of the University of California system .