An American freelance journalist held captive for nearly two years by Al Qaeda’s branch in Syria was freed on Sunday in a handover to United Nations peacekeepers in the Golan Heights, who then released him to United States government officials.

New York Times reports that the freelance journalist, Peter Theo Curtis, 45, from Boston, was abducted near the Syria-Turkey border in October 2012. He was held by the Nusra Front, the Qaeda affiliate in Syria, which has broken with the even more radical Islamic State in Iraq and Syria, or ISIS. Another American journalist, James W. Foley, who was kidnapped in Syria the following month, was beheaded last week by ISIS, which posted the images of his death on YouTube.

The United Nations confirmed in a statement on its website that Mr. Curtis was transferred to the custody of the United Nations peacekeeping force in Al Rafid village, in the disputed Golan Heights region straddling Syria and Israel, at 6:40 p.m. local time.

Mr. Curtis’s extended family released a statement thanking the governments of the United States and Qatar and “the many individuals, private and public, who helped negotiate the release of our son, brother and cousin.”

Nancy Curtis, the journalist’s mother, asserted in the statement that his release was secured without any ransom payment, one of the primary motivations for such abductions by the Nusra Front, ISIS and affiliated groups. It remains unclear what Mr. Curtis’s captors received, if anything, for releasing him.

“While the family is not privy to the exact terms that were negotiated, we were repeatedly told by representatives of the Qatari government that they were mediating for Theo’s release on a humanitarian basis without the payment of money,” Mrs. Curtis said.

President Obama and Secretary of State John Kerry welcomed the news, coming less than a week after the beheading of Mr. Foley had focused world attention on how the administration was confronting the ascendance of radical Islamic militancy in the Middle East, particularly ISIS.

“The president shares in the joy and relief that we all feel now that Theo is out of Syria and safe,” Eric Schultz, a White House spokesman, said. “But we continue to hold in our thoughts and prayers the Americans who remain in captivity in Syria, and we will continue to use all of the tools at our disposal to see that the remaining American hostages are freed.”

Mr. Kerry acknowledged that “after a week marked by unspeakable tragedy, we are all relieved and grateful knowing that Theo Curtis is coming home.” In a statement posted on the State Department website, Mr. Kerry also said: “Over these last two years, the United States reached out to more than two dozen countries asking for urgent help from anyone who might have tools, influence, or leverage to help secure Theo’s release and the release of any Americans held hostage in Syria.”

In a video dated July 18 and obtained by The New York Times, Mr. Curtis is seen disheveled, with long unkempt hair and bound hands, with an armed man holding an automatic weapon at his side. Mr. Curtis begs for his life, saying: “I have three days left. Three days — please do something.” A video released just weeks earlier, on June 30, had a different tone. Speaking from a script, he says his captors had treated him well and that he “had everything” he needed.

“Everything has been perfect — food, clothing, even friends,” he says in the footage.