The parents of an American hostage killed in the custody of Islamic State of Iraq and the Levant (ISIL) said it brought them solace to know the US military dedicated to her the special forces operation that killed its leader, Abu Bakr al-Baghdadi.

US President Donald Trump confirmed the death of al-Baghdadi in Syria‘s northwest Idlib province on Sunday, announcing from the White House the United States had “brought the world’s number one terrorist leader to justice”.

In his address, Trump mentioned Kayla Mueller, a 26-year-old aid worker kidnapped by ISIL after she crossed the Turkish border into Syria to visit a hospital in August 2013.

In February 2015, American officials confirmed Mueller’s death. Her body has never been found.

“Think of the things he did to Kayla… What he did to her was incredible,” Trump said. “He kept her in captivity for a long period of time; he kept her in captivity, his personal captivity. She was a beautiful woman, beautiful young woman, helped people.

“He was an animal and he was a gutless animal,” he added.

‘Not forgotten’

Commenting on Trump’s speech, her father Carl Mueller told ABC News on Sunday that Trump’s dedication of the military operation to his daughter was “very touching”.

“President Trump mentioned her today in his statement and he mentioned that he deserved what he [al-Baghdadi] got for what he did to Kayla… She’s not forgotten, and that’s important.”

Speaking to The Arizona Republic, Mueller said: “She was held in many prisons. She was held in solitary confinement. She was tortured. She was intimidated. She was ultimately raped by al-Baghdadi himself.

“He either killed her or he was complicit in her murder.”

Her mother, Marsha Mueller, said she hopes more information will emerge about her daughter.

“I still want to know, where is Kayla and what truly happened to her and what aren’t we being told?” she said. “Someone knows and I’m praying with all my heart that someone in this world will bring us those answers.”

At the time of her death in 2015, Mueller’s parents said their daughter had devoted her career “to helping those in need in countries around the world”, since graduating from Northern Arizona University in 2009.

Mueller lived and worked with humanitarian aid groups in northern India, Israel, and the occupied Palestinian territories before returning to Arizona in 2011 and working at an HIV/AIDS clinic and a women’s shelter.

Sensitive intelligence

The death of al-Baghdadi marks a significant foreign policy success for Trump, coming at one of the lowest points in his presidency as he is mired in impeachment proceedings.

Eight military helicopters flew for more than an hour over territory controlled by Russian and Syrian forces, Trump said, before landing under gunfire at a compound. Planning for the operation began two weeks ago, the president said, after the US gained unspecified intelligence on al-Baghdadi’s whereabouts.

No US troops were hurt in the operation, said Trump, adding sensitive information was taken from the ISIL compound by US special forces.