The Obama administration announced Tuesday that it had released hundreds of illegal immigrants held in detention facilities, saying it could no longer afford to house them because of across-the-board cuts that are set to start taking effect Friday.

Federal authorities said that the detainees continue to face immigration charges, that they are being monitored and that violent offenders will not be let go.

The unusual action came as much of Washington plotted strategy for managing the deep cuts, known as sequestration, and for winning the political battle over them.

President Obama flew to Newport News to highlight the effect the reductions would have on the defense industry, saying they would harm a facility that builds nuclear submarines. Other top administration officials joined in, with Attorney General Eric H. Holder Jr. bluntly declaring in a speech, “The American people are going to be less safe.”

Politically, the president seemed to be trying to cause a split between Republican lawmakers who are set against raising taxes as part of a compromise to avoid the spending cuts and those who are open to the idea.

You’ve heard the word “sequester” mentioned by politicians a lot lately. The Washington Post’s Ed O’Keefe explains what the term means, and why it matters. (The Washington Post)

Obama heralded Rep. Scott Rigell (R-Va.) for endorsing an overhaul of the tax code that raises new revenue, bringing him to Newport News on Air Force One. He also met later in the day with Republican Sens. Lindsey O. Graham (S.C.) and John McCain (Ariz.), who have signaled that they would be open to more taxes as part of a broader compromise that also overhauled entitlements.

But GOP leaders showed no such interest Tuesday. House Speaker John A. Boehner (Ohio) lashed out at Obama, saying he was exploiting members of the armed services to achieve political aims.

“I don’t think the president’s focused on trying to find a solution to the sequester,” he said at a news conference. “The president has been traveling all over the country and today [is] going down to Newport News in order to use our military men and women as a prop in yet another campaign rally to support his tax hikes.”

With the sequester all but certain to begin Friday, Republicans and Democrats were positioning for a longer brawl that would last until at least late March, when a stopgap measure that funds the government expires.

The administration has acknowledged that the full brunt of the sequester wouldn’t be felt until near then, and both sides are looking to that battle to determine whether the cuts remain — and whether the government shuts down.

Senate Democrats are planning to advance a proposal before Friday that would halt much of the across-the-board reductions through the end of the year and replace them with a combination of other cuts and tax increases, including a new minimum tax rate for those making more than $5 million a year. It is not expected to get the 60 votes necessary to overcome a Republican filibuster.

Republicans are divided about their strategy. Senate Republicans had planned to push for a bill that would preserve the $85 billion in cuts for this fiscal year but give the administration greater flexibility in how to manage them.

But McCain, Graham and other GOP senators say they oppose handing over the appropriations power, usually the domain of Congress, to the White House, and Senate Minority Leader Mitch McConnell (Ky.) said Tuesday that Republicans are still plotting their legislative strategy. In any case, Democrats are expected to reject any GOP proposal that would leave the scale of the cuts intact.

Obama seems intent on capitalizing on divisions within the GOP. In Newport News, he said more Republicans need to follow in the footsteps of Rigell and McCain.

“I’ve got to give Scott Rigell credit. He is one of your Republican congressmen who’s with us here today — and that’s not always healthy for a Republican, being with me,” Obama said. “But the reason he’s doing it is because he knows it’s important to you. And he’s asked his colleagues in the House to consider closing tax loopholes instead of letting these automatic cuts go through.”

Rigell told reporters on Air Force One that although the country needs to cut spending, “I also believe that revenue has to come up a bit, first by growing the economy, but also by tax reform, which also includes eliminating lobbyist-inspired, lobbyist-written loopholes.”

Republican leaders seemed uninterested, though, and announced that their first big bill of the year would be an overhaul of the tax code that would not raise the overall tax burden. In exchange for scaling back tax breaks, Republicans plan to lower rates.

“I’m not interested in new revenue at this point,” House Ways and Means Committee Chairman Dave Camp (R-Mich.) said Tuesday.

With its decision to release detainees in immigration facilities, the Obama administration sought to make clear the impact of the sequester.

The move drew heavy GOP criticism. “The last thing you would do to meet a budget cut of this size would be to voluntarily undertake actions that undermine the rule of law and endanger the public safety,” said Sen. Jeff Sessions (Ala.).

House Speaker John A. Boehner (Ohio) said in an interview on CBS, “I, frankly, think this is outrageous.”

Historically, many illegal immigrants released from federal detention centers while in deportation proceedings do not show up for subsequent court appearances, joining the ranks of what the Immigration and Customs Enforcement calls absconders or “fugitive aliens.”

The agency has estimated that detention costs $122 per bed per day. It has been under pressure by immigration advocacy and civil rights groups to rely on cheaper detention alternatives for those in deportation proceedings who do not pose a security threat. More cost-effective alternatives include electronic ankle-bracelet monitoring, telephone monitoring and community-based monitoring programs.

In a news briefing Monday before the releases were announced, Homeland Security Secretary Janet Napolitano indicated that sequestration would affect detention policy. “I’m supposed to have 34,000 detention beds for immigration,” she said. “How do I pay for those?”

William Branigin, Sari Horwitz, Paul Kane, Lori Montgomery and Tara Bahrampour contributed to this report.