Kevin Lamarque / Reuters President Barack Obama speaks about the continuing government shutdown during a news conference from the White House Briefing Room in Washington, October 8, 2013.

In a marathon news conference designed to emphasize the dire consequences of failing to raise the debt ceiling, President Barack Obama upped the pressure on congressional Republicans Tuesday to lift the borrowing cap and reopen the government without conditions or delay.

Democrats, Obama said from the White House briefing room, “have shown more than ample willingness to talk about any issues that the Republicans are concerned about. But we can’t do it if the entire basis of the Republican strategy is, ‘we’re going to shut down the government or cause economic chaos if we don’t get a hundred percent of what we want.’ So my suggestion to [House Speaker John Boehner] has been and will continue to be, ‘let’s stop the excuses, let’s take a vote in the House, let’s end this shutdown right now, let’s put people back to work.'”

Obama quoted financial experts saying that failure to raise the debt limit is “insane, catastrophic, chaos,” adding, “these are some of the more polite words.” Obama added for the skeptics, “this is real.” If Congress doesn’t act, the government will not be able to pay all of its bills beginning Oct. 17, according to the Treasury Department.

(MORE: Obama and Boehner Have a Phone Chat, But No End To Shutdown Impasse)

Speaking for more than an hour and taking questions from 11 reporters, Obama expressed openness to a House Republican proposal to create a new fiscal negotiating committee, in exchange for a short-term agreement to raise the debt limit and reopen government.

“If there’s a way to solve this, it has to include reopening the government and saying America is not going to default; it’s going to pay our bills,” Obama said, reiterating what has been his position for the past several weeks. “[Republicans] can attach some process to that that gives them some certainty that in fact the things they’re concerned about will be topics of negotiation, if my word’s not good enough. If they want to specify all the items that they think need to be topic of conversation, happy to do it.”

In a statement after Obama’s remarks, Boehner said that Obama will have to budge from his no-negotiating position if he wants the government to reopen and the debt limit raised. “The long and short of it is, there is going to be a negotiation here,” he said.

Senate Democrats have come out against the GOP proposal, with Senate Budget Committee Chairwoman Patty Murray saying Tuesday in a statement that “this Republican gimmick is intended to keep two crises going while they again refuse to make any concessions.”

But Obama emphasized that he won’t act until Boehner reopens the government, saying “extortion” can’t be made “routine.”

“And this is not just for me; it’s also for my successors in office,” Obama said. “Whatever party they’re from, they shouldn’t have to pay a ransom either for Congress doing its basic job. We’ve got to put a stop to it.”

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Obama said that the Treasury Department is “exploring all contingencies” if Congress doesn’t act by next Wednesday, the day extraordinary borrowing measures run out and the government is left to pay its bills with only its day-to-day cash. “But let me be clear — no option is good in that scenario,” Obama added. “There is no silver bullet. There is no magic wand that allows us to wish away the chaos that could result if, for the first time in our history, we don’t pay our bills on time.”

The president admitted that he is “tempted” to sign House Republicans’ piecemeal approaches to reopen narrow swaths of the federal government, which has been partially shutdown for a week now, but said he’s decided against it because “if there’s no political heat, if there’s no television story on it, then nothing happens.”

“You don’t do a piecemeal approach like that when you’re dealing with a government shutdown, OK,” he said.

Boehner said earlier in the day that it’s past time for Obama to negotiate in good faith. The two spoke by phone on Tuesday morning.

“All we’re asking for is to sit down and have a conversation,” Boehner said. “There’s no reason to make it more difficult to bring people to the table. There’s no boundaries here, there’s nothing on the table, there’s nothing off the table. I’m trying to do everything I can to bring people together and have a conversation.”