American journalist Peter Theo Curtis says he has been "overwhelmed with emotion" at being home after 22 months in detention in Syria.

"I had no idea when I was in prison … so much effort was being expended on my behalf," Curtis told reporters outside his mother's home in Cambridge, Mass., on Wednesday, 

"Now having found out, I am overwhelmed with emotion."

He promised to say more to journalists and answer their questions at some point in the future, but for now, he has to "bond with my mother" and family.

"I'm also overwhelmed by … total strangers … coming up to me and saying, 'We're just glad you're home, welcome home, glad you're back. glad you're safe ….' I suddenly remember how good the American people are and what kindness they have in their hearts.

"And to all those people, I say a huge thank you from my heart — from the bottom of my heart."

He said he had no idea during his incarceration how may people were working to get him freed.

Curtis, 45, said Tuesday he was "deeply indebted" to the U.S. officials who worked to get him released by al-Nusra Front, a Sunni extremist group.

Another held by Syrian government

Last week, American journalist James Foley, who also was kidnapped in 2012 while covering the Syrian uprising, was killed. The Islamic State group posted a video showing his beheading.

The extremists said they killed the native of Rochester, N.H., in retaliation for U.S. airstrikes targeting Islamic State positions in northern Iraq.

Curtis's mother Nancy said in a statement Tuesday night she was "overwhelmed with relief" that her son had been returned to her.

"But this is a sober occasion because of the events of the past week," she said. "My heart goes out to the other families who are suffering."

U.S. freelance journalist Austin Tice of Houston disappeared in Syria in August 2012. He is believed to be held by the Syrian government.

With files from The Associated Press