At the White House, President Barack Obama noted that more than 4,000 FAA workers have been furloughed, more than 70,000 construction workers have stopped working on FAA projects and the country stands to lose $1 billion in tax revenue from airline ticket taxes that can't be collected during the shutdown.
"So this is a lose-lose-lose situation," he said.
Earlier in the day, Transportation Secretary Ray LaHood, a Republican, took the podium in the White House briefing room to urge Congress to return from its just-started break to resolve the partisan standoff behind the shutdown, now in its 12th day.
Obama noted later they have a procedural way of ending the shutdown without coming back.
"And they can have the fights that they want to have when they get back," he said. "Don't put the livelihoods of thousands of people at risk, don't put projects at risk, and don't let $1 billion at a time when we're scrambling for every dollar we can, get off the table because Congress did not act."
The president said his "expectation, and I think the American people's expectation is that this gets resolved before the end of this week."
If Congress doesn't work on a deal, White House spokesman Jay Carney said "we will look at the measures the president may be able to take."
Democrats want a bill with no strings attached, and said at a Capitol Hill news conference that they could still pass a bill that would get the FAA working again, but they need Republican cooperation.
Rep. John Mica, R-Fla., chairman of the House Transportation and Infrastructure Committee, told The Associated Press that House GOP leaders will only agree to their own bill with $16.5 million spending cuts to subsidies for air service to rural communities. That's the same measure that provoked the standoff.
So far, neither side is blinking.
LaHood took a strong blast at members of Congress from both parties, saying when it comes to creating jobs "they talk the talk, but they have not walked the walk."
Obama also raised the specter of safety being compromised, even though LaHood has repeatedly offered reassurances that safety workers like air traffic controllers and maintenance crews were on the job. Forty safety inspectors were furloughed but are continuing to work, traveling on their own credit cards.
Pressed on what options Obama had if Congress doesn't return voluntarily, Carney said fixing the crisis was Congress' job.
"We are intently interested in assuring that these 74,000 Americans who had jobs get them back," he said. Because they were essentially "thrown out of work by a failure of Congress to act," the simplest solution was for lawmakers to come back to Washington and fix the problem.
After passing a contentious bill to raise the government's debt ceiling, the House and Senate earlier this week left town for their annual summer recess.
"Congress needs to come back, resolve their differences, and compromise...They should not leave 74,000 people hanging out there," LaHood said.
Despite the shutdown, air traffic controllers have remained on the job. LaHood has vowed that air safety won't be compromised.
Associated Press writer Tom Raum and Ben Feller contributed to this report.