The Pentagon will make "some very quick decisions" on programs to be hit by automatic spending cuts under the so-called sequester, a Defense Department spokesman said Thursday.

"We will have to make some very quick decisions about programs that we may need to pare back and so forth as a result of sequestration," Pentagon spokesman George Little told reporters, as time ticked away to reach a possible deal to avert the cuts.

"We remain hopeful that some 11th hour deal can be reached by the Congress," Little said during a press briefing.

"This is a deeply problematic situation for this Department and for others. We hope to avert it," he said.

He added that "prospects aren't looking particularly good" to avoid the cuts, which go into effect on Friday.

The Pentagon has warned that US military readiness could be hurt and public and emergency services curtailed if the cuts go through.

Little said that "not everything will happen on day one," suggesting that trims to some military programs might be phased in later if a deal is not reached.

Obama invited congressional leaders to the White House on Friday -- the day the $85 billion in across-the-board cuts hit -- for talks to avert the sequester.

The painful, automatic budget cuts were envisioned as a mechanism to ensure the success of talks to cut the deficit, but no agreement has been reached and the sequester now is just hours away.

Republicans blame Obama for the stalemate, saying the sequester was his idea; the White House notes that the measure was endorsed by Congress, and at any rate, was never envisioned to actually go into force but rather as an incentive to get lawmakers to act on the deficit and national debt.