He said the United States had previously repatriated 14 other Algerians and was “satisfied that the Algerian government would continue to abide by lawful procedures and uphold its obligations under domestic and international law in managing the return of former Guantánamo detainees.”

“We understand that from time to time we will receive criticism,” Mr. Moss said, “but we are absolutely committed to moving forward with closing Guantánamo, and doing so in a responsible manner, consistent with the law, our national security interests and our longstanding humane treatment policies.”

Mr. Ameziane was arrested in Pakistan in late 2001, and the other Algerian, Belkacem Bensayah, was arrested in Bosnia in 2001. Both were taken to Guantánamo in early 2002. The two men were approved for transfer, if security conditions could be met, by a 2009 Obama administration task force.

“Mr. Bensayah was adamant that he would rather stay at Guantánamo than return to Algeria,” said Mark Fleming, a lawyer for Mr. Bensayah, “not only because he wanted to be reunited with his family in Bosnia after 12 years apart, which now seems increasingly difficult — if not impossible — but he also feared he would be a target for actual extremists in Algeria.”

Mr. Fleming said Mr. Bensayah’s legal team had unsuccessfully sought to persuade Bosnia, which had revoked his citizenship, to take in his client because his wife and daughters live there. He said the United States should have tried harder to get another European country to take him.

In a news release, the Center for Constitutional Rights called Mr. Ameziane’s involuntary transfer “as unnecessary as it is bitterly cruel,” and said he should have been sent instead to Canada — he once lived in Montreal — or to Luxembourg, which the center contended offered in 2010 to take him in.

Luxembourg’s interest has been murky. Jennifer Oscroft, a British lawyer who assisted in efforts to resettle Mr. Ameziane, said in an interview that it had been a “serious opportunity” because a top Luxembourg official expressed sympathy for Mr. Ameziane and that the country sent a delegation to Guantánamo in mid-2010 to interview him.