CIA Director John Brennan said he disagrees with presumptive Republican presidential nominee Donald Trump that waterboarding detainees advances national security investigations, and said he would resign if "the next president" ordered him to resume such controversial interrogation techniques.
Brennan said during an event at the Brookings Institution think tank on Wednesday that the next president could order expanded drone attacks or remove the ban on waterboarding, but the final decisions are up to the director of CIA and their agency colleagues. He then said if the next president wanted to resume waterboarding "they'll have to find another director," but did not mention Trump by name.
Brennan said in April he would reject an order to resume waterboarding because the CIA as an "institution needs to endure." Trump later called Brennan's April comments "ridiculous."
The former reality show host has said "torture works" and has tried to portray himself as a law-and-order candidate. During a rally on April 20 in Indianapolis he added, "I love it...we should make it much tougher than waterboarding."
President Barack Obama banned the use of waterboarding in 2009, calling it torture and thus a violation of international law. A Senate Intelligence Committee report completed in 2014 showed that the waterboarding of three suspected militants detained in secret foreign prisons during the Bush administration was ineffective at producing intelligence on terrorism.
Former CIA operatives have told U.S. News that the use of enhanced interrogations techniques like waterboarding reflect how the agency has faced crises of ethics and identity since the end of the Cold War.
See photos of John Brennan through the years
CIA Director John Brennan through the years
CIA Director John Brennan through the years
WASHINGTON, DC - JANUARY 07: U.S. President Barack Obama (L) speaks as Acting CIA Director Michael Morell (R) and Deputy National Security Advisor for Homeland Security and Counterterrorism John Brennan (2nd L) listen while making personnel announcements during an event in the East Room at the White House, on January 7, 2013 in Washington, DC. President Obama has nominated Hagel for the next Secretary of Defense and Brennan to become the new director of the CIA. (Photo by Alex Wong/Getty Images)
James Clapper (R), Director of National Intelligence, testifies alongside CIA Director John Brennan (L), during a US House Committee on Intelligence hearing on Capitol Hill in Washington, DC, September 10, 2015. The committee held the hearing to examine worldwide cyber threats. AFP PHOTO / SAUL LOEB (Photo credit should read SAUL LOEB/AFP/Getty Images)
WASHINGTON, DC - JANUARY 31: Assistant to the President for Homeland Security and Counterterrorism John Brennan (L), U.S. President Barack Obama's nominee to be CIA director, meets with U.S. Senate Select Committee on Intelligence Chairman Dianne Feinstein (D-CA) at Feinstein's office at Hart Senate Office Building January 31, 2013 on Capitol Hill in Washington, DC. Brennan met with Feinstein who will hold a hearing to start the confirmation process of Brennan's nomination. (Photo by Alex Wong/Getty Images)
Anti-war protesters shout slogans as John Brennan (R), President Barack Obama's pick to lead the CIA, arrives to testify before a full committee hearing on his nomination to be director of the Central Intelligence Agency (CIA) in the Hart Senate Office Building in Washington, DC, on February 7, 2013. AFP PHOTO/Jewel Samad (Photo credit should read JEWEL SAMAD/AFP/Getty Images)
John Brennan, US President Barack Obama's pick to lead the CIA, testifies before a full committee hearing on his nomination to be director of the Central Intelligence Agency (CIA) in the Hart Senate Office Building in Washington, DC, on February 7, 2013. AFP PHOTO/Jewel Samad (Photo credit should read JEWEL SAMAD/AFP/Getty Images)
UNITED STATES - MARCH 12: CIA Director John Brennan testifies during the Senate (Select) Intelligence Committee hearing on 'Current and Projected National Security Threats to the United States' on Tuesday, March 2013. (Photo By Bill Clark/CQ Roll Call)
NEW YORK, NY - AUGUST 08: General Keith B. Alexander, Director of the National Security Agency (NSA) and Commander of U.S. Cyber Command (L); John O. Brennan, Director of the Central Intelligence Agency (CIA) (C); and Robert S. Mueller III, Director of the Federal Bureau of Investigation (FBI) (R), take part in a question-and-answer forum during the International Conference on Cyber Security (ICCS) on August 8, 2013 in New York City. The ICCS, which is co-hosted by Fordham University and the FBI, is held every 18 months; more than 25 countries are represented at this year's conference. (Photo by Andrew Burton/Getty Images)
WASHINGTON, DC - MARCH 11: Central Intelligence Agency Director John Brennan delivers remarks at the Council on Foreign Relations March 11, 2014 in Washington, DC. Brennan denied accusations by U.S. senators who claim the CIA conducted unauthorized searches of computers used by Senate Select Committee on Intelligence staff members in an effort to learn how the committee gained access to the agencyÃs own 2009 internal review of its detention and interrogation program, undermining CongressÃ oversight of the spy agency. (Photo by Chip Somodevilla/Getty Images)
Director of Central Intelligence Agency John Brennan speaks during a press conference at CIA headquarters in Langley, Virginia, December 11, 2014. The head of the Central Intelligence Agency acknowledged Thursday some agency interrogators used 'abhorrent' unauthorized techniques in questioning terrorism suspects after the 9/11 attacks. CIA director John Brennan said there was no way to determine whether the methods used produced useful intelligence, but he strongly denied the CIA misled the public. AFP PHOTO/JIM WATSON (Photo credit should read JIM WATSON/AFP/Getty Images)
WASHINGTON, USA - SEPTEMBER 10: CIA Director John Brennan testifies during a House Select Committee on Intelligence hearing on Cyber Security and the threat of Cyber Attacks in Washington, USA on September 10, 2015. (Photo by Samuel Corum/Anadolu Agency/Getty Images)
FILE - In this Dec. 11, 2014 fie photo, CIA Director John Brennan listens during a news conference at CIA headquarters in Langley, Va. An anonymous hacker claims to have breached CIA Director John Brennanâs personal email account and has posted documents online, including a list of email addresses purportedly from Brennanâs contact file. (AP Photo/Pablo Martinez Monsivais, File)