Washington (CNN) - President Barack Obama called on lawmakers Wednesday to overcome the "selfish" norms of politics and "do their job" in order to strike a deal on raising the federal government's current $14.3 trillion debt ceiling by the start of August.

People shouldn't get "spooked," but "the yellow light (is) flashing," he warned. "This is urgent."

Top economic analysts have warned of potentially catastrophic repercussions if the ceiling is not raised by August 2, including skyrocketing interest rates and a plummeting U.S. dollar.

The president blasted congressional Republicans for refusing to consider raising taxes on the wealthiest Americans as part of any deal. Congress needs to be willing to "take on their sacred cows and do tough things" while moving away from "maximalist positions," he said.

He said Congress should cancel upcoming summer vacations if a deal isn't struck by the end of the week.

"I want everybody to understand that this is a jobs issue. This is not an abstraction," he said. "If the United States government, for the first time, cannot pay its bills - if it defaults - then the consequences for the U.S. economy will be significant and unpredictable. And that is not a good thing."

Obama made his remarks during a wide-ranging news conference covering the state of the economy, the wars in Afghanistan and Libya, and hot-button social issues such as same-sex marriage. It came at a time of rising questions over Obama's ability to maintain control of the political narrative and boost public confidence in his stewardship in the run-up to next year's presidential election.

GOP leaders have shown no signs of yielding in their opposition to higher taxes as part of any grand bargain with the White House. Recent bipartisan talks led by Vice President Joe Biden collapsed over the tax disagreement.

"The president is sorely mistaken if he believes a bill to raise the debt ceiling and raise taxes would pass the (Republican-controlled) House," Speaker John Boehner, R-Ohio, said after Obama's news conference.

"A debt-limit increase can only pass the House if it includes spending cuts larger than the debt limit increase; includes reforms to hold down spending in the future; and is free from tax hikes," Boehner added. "The longer the president denies these realities, the more difficult he makes this process."

Senate Minority Leader Mitch McConnell, R-Kentucky, insisted earlier in the day that Republicans will "refuse to let the taxpayers take the hit when it comes to reducing the debt."

The debate is "about holding Washington accountable for a change," McConnell said. "It's about refusing to subsidize the Democrats' irresponsible spending habits another day."

For his part, the president ripped Republicans for protecting "millionaires and billionaires," oil companies, hedge fund managers, and owners of corporate jets.

The wealthy, he said, can afford to pay higher taxes.

"You can still ride on your corporate jet. You're just going to pay a little more," Obama said.