The effort was part of a burst of urgent, high-level diplomatic talks aimed at moving as many as possible of Guantánamo’s 22 prisoners who are recommended for transfer. By law, the Pentagon must notify Congress 30 days before a transfer, so the deadline to set in motion deals before the end of the Obama administration was Monday.

By late in the day, officials said, the administration had agreed to tell Congress that it intended to transfer 17 or 18 of the 59 remaining detainees at the prison; they would go to Italy, Oman, Saudi Arabia and the United Arab Emirates. If all goes as planned, that will leave 41 or 42 prisoners in Guantánamo for Donald J. Trump’s administration. Mr. Trump has vowed to keep the prison operating and “load it up with some bad dudes.”…

Elisa Massimino, the president of Human Rights First, said that even though it appears likely that failing to fulfill his vow to close the Guantánamo prison will be part of Mr. Obama’s legacy, it was still “incredibly important” that his administration did not let up on the effort to get out those men who were deemed transferable, if security conditions could be met, after a six-agency review.