WASHINGTON — President Obama said Tuesday that he would recommit himself to closing the Guantanamo Bay prison, a goal that he all but abandoned in the face of congressional opposition in his first term and that faces steep challenges now.
‘‘It’s not sustainable,’’ Obama said at a White House news conference. ‘‘The notion that we’re going to keep 100 individuals in no man’s land in perpetuity,’’ he added, makes no sense. ‘‘All of us should reflect on why exactly are we doing this? Why are we doing this?’’
Describing the prison as a waste of taxpayer money that has had a damaging effect on US foreign policy, Obama said he would try again to persuade Congress to lift restrictions on transferring inmates. He also said he had ordered a review of ‘‘everything that we can do administratively.’’
But there is no indication that Obama’s proposal to close the prison in Cuba, as he vowed to do upon taking office in 2009 after criticizing it during the presidential campaign, has become any more popular. Obama remarked that ‘‘it’s a hard case to make’’ because ‘‘it’s easy to demagogue the issue.’’
The plan for Guantanamo he proposed — moving any remaining prisoners to a supermax-style prison in Illinois — was blocked by Congress, which barred any further transfers of detainees onto domestic soil.
A spokesman for Senator Mitch McConnell of Kentucky, the Republican Senate leader and one of the leading opponents of closing the prison, said on Tuesday that ‘‘there is wide, bipartisan opposition in Congress to the president’s goal of moving those terrorists to American cities and towns.’’
Obama made his remarks following the arrival at the prison of more than three dozen Navy nurses, corpsmen, and specialists to help deal with a mass hunger strike by inmates, many of whom have been held for more than 11 years without trial.
As of Tuesday, 100 of the 166 prisoners were officially deemed to be participating, with 21 now being force-fed a nutritional supplement through tubes inserted in their noses.
“I don’t want these individuals to die,’’ Obama said.
Both conservatives and civil libertarians said that under existing law, Obama could be doing more to reduce the number of low-level detainees held at the prison.
The chairman of the House Armed Services Committee, Representative Howard P. McKeon, Republican from California, said the Obama administration had never exercised the power it has had since 2012 to waive, on a case-by-case basis, most of the restrictions lawmakers have imposed on transferring detainees to countries with troubled security conditions.
‘‘For the past two years, our committee has worked with our Senate counterparts to ensure that the certifications necessary to transfer detainees overseas are reasonable,’’ McKeon said. ‘‘The administration has never certified a single transfer.’’
Human rights groups also urged Obama to direct the Pentagon to start issuing waivers, and said he should appoint a White House official to run Guantanamo policy with the authority to resolve interagency disputes.
For example, because of disagreements over evidence tainted by torture, the administration has missed by more than a year a deadline to begin parole-style hearings by so-called Periodic Review Boards.
“There’s more to be done, but these are the two essential first steps the president can take now to break the Guantanamo logjam,’’ said Anthony D. Romero, executive director of the American Civil Liberties Union.
Obama was ambiguous about one of the most difficult problems raised by Guantanamo: what to do with dozens of detainees deemed too risky to release but not feasible to prosecute. His policy has been not to release those prisoners, but to continue to imprison them indefinitely under the laws of war — just somewhere else.
Yet at another point, Obama appeared to question that policy at a time when the war in Iraq has ended, the one in Afghanistan is winding down and the original makeup of Al Qaeda has been decimated.
‘‘The idea that we would still maintain forever a group of individuals who have not been tried,’’ he said, ‘‘that is contrary to who we are, contrary to our interests, and it needs to stop.’’