In this photo released Jan. 18, 2002, by the Department of Defense, al-Qaeda and Taliban detainees in orange jumpsuits sit in a holding area called Camp X-Ray under guard by U.S. military police at Guantanamo Bay, Cuba. (SHANE T. MCCOY/Agence France-Presse/U.S. Navy)

The last time there were fewer than 100 detainees at Guantanamo Bay, Cuba, was Jan. 16, 2002.

That month, shortly after the military prison opened, detainees in orange jumpsuits arriving from overseas locations were forced onto their knees in outdoor pens. Their wrists were bound, their hands covered with mittens. To isolate the men from their surroundings, their eyes were covered and they wore industrial earmuffs. It became an enduring image of the excesses of America’s response to the Sept. 11, 2001, attacks.

This week, with the expected resettlement of 10 Yemeni detainees, the prison population will once again dip below 100, this time symbolizing President Obama’s sprint to close Guantanamo before he leaves office.

During his final State of the Union speech on Tuesday, Obama said that closing the prison at Guantanamo Bay would set a positive example for the rest of the world.

“It is expensive, it is unnecessary, and it only serves as a recruitment brochure for our enemies,” Obama said of the prison. “There’s a better way.”

With its history of hunger strikes, harsh treatment and byzantine military court proceedings, Guantanamo Bay is now tied up with Obama’s legacy as much as it is with that of George W. Bush, who sent hundreds of prisoners there.

On his first day in office, Obama promised to close the prison, but his plans have been held up for years amid internal disagreements and steadfast opposition in Congress.

After this week’s transfer, there will be 93 prisoners at Guantanamo, including dozens who have lingered for years after being cleared by a government board for release.

Sen. Kelly Ayotte (R-N.H.), a leading critic of Obama’s handling of Guantanamo, criticized the transfer, which is expected to be announced Thursday.

“Any Obama administration decision to transfer a large number of Yemeni detainees from Guantanamo to Oman would represent a thinly veiled attempt to undercut the will of Congress and would further endanger the American people,” Ayotte said in a statement.

Pentagon spokesman Peter Cook said that Defense Secretary Ashton B. Carter has “deliberately and carefully scrutinized” potential transfers in keeping with Obama’s closure goal. “He only agrees to transfers when he is satisfied that appropriates steps have been taken to mitigate risk to the United States,” Cook said.

Administration officials said they would not discuss the details of the transfer until it is completed.

The resettlement brings to 14 the number of detainees transferred out of Guantanamo this year. A recent uptick in successful transfers is an indication of growing momentum at the Pentagon, where the Guantanamo endgame has emerged as a high-stakes political issue.

In early 2015, Defense Secretary Chuck Hagel was forced out in large part over his refusal to expedite the Guantanamo transfers, which were viewed with suspicion by military officials who worried released prisoners would take up arms again.

Carter, taking over for Hagel in the crucial final period of Obama’s presidency, faces intense pressure to deliver on one of the president’s highest priorities.

One former senior official, who spoke on the condition of anonymity to discuss internal proceedings, said Carter’s team, after almost a year on the job, appeared to have broken a logjam within the Pentagon bureaucracy, which many officials said had stalled transfer approvals for years.

The State Department is responsible for negotiating resettlement and repatriation deals for the prisoners, who are in military custody. Administration officials are now hoping to resettle all those cleared for release by summer.

As the pace of transfers accelerates, officials are also racing to finalize a plan they must submit to Congress outlining steps the White House hopes to take to end detention operations at Guantanamo, including bringing some prisoners to the United States for trial or indefinite detention without charge.

But fierce congressional opposition to previous closure attempts is unlikely to subside.

Guantanamo is “the perfect place for terrorists,” Senate Majority Leader Mitch McConnell (R-Ky.) said this week.

Among the impediments to White House closure plans is local opposition and disagreement among administration officials about where to put prisoners brought to the United States.

During Obama’s address on Tuesday night, Republican lawmakers from Kansas, Colorado and South Carolina, home to some of the detention sites being considered by the White House, reiterated their opposition to Obama’s plans.

Prisoners “do not belong back on the battlefield fighting against us, nor do they belong on U.S. soil,” said Sen. Cory Gardner (Colo.). He called Obama’s plan “misguided.”

For months White House officials have hinted that Obama may resort to executive action to close the prison if lawmakers refuse to cooperate.

Cliff Sloan, a former State Department special envoy for Guantanamo closure, said the president had constitutional authority to bring prisoners to the United States despite a law that prohibits the administration from spending money on bringing them onto U.S. soil.

“When it’s down to a very small number, such as those who are facing charges in the military commissions, that’s exactly what he should do,” Sloan said. “The congressional restrictions that require holding detainees in a particular location are blatantly unconstitutional, and they’re completely at odds with our history of law of war detention.”

Laura Pitter, senior national security counsel at Human Rights Watch, warned that the Obama administration will only perpetuate a flawed system if it uses mainland facilities to imprison inmates it deems too dangerous to release but cannot be tried in military or civilian courts.

“What’s important to us is not just closing Guantanamo but ending indefinite detention without charge or trial,” Pitter said.

Julie Tate and Adam Goldman contributed to this report.