NEW YORK — A day after flight delays plagued much of the nation, air travel was smoother Tuesday, but the government warned passengers that the situation could change by the hour as thousands of air-traffic controllers are forced to take furloughs because of budget cuts.


Meanwhile, airlines and members of Congress urged the Federal Aviation Administration to find other ways to reduce spending. Airlines are worried about the long-term costs late flights will have on their budgets and on passengers.


“I just can’t imagine this stays in place for an extended period of time. It’s just such terrible policy,” US Airways CEO Doug Parker said. “We can handle it for a little while, but it can’t continue.”


The delays are the most visible effect yet of Congress and the White House’s failure to agree on a long-term deficit-reduction plan.


Transportation Secretary Ray LaHood said no one should be surprised, noting that he warned about the potential for problems two months ago.


His solution: Blame Congress for the larger budget cuts that affected all of government, including a $600 million hit to the Federal Aviation Administration.


“This has nothing to do with politics,” LaHood said. “This is very bad policy that Congress passed, and they should fix it.”


Critics of the FAA insist the agency could reduce its budget in other ways that would not inconvenience travelers.


Sens. John D. Rockefeller IV, a West Virginia Democrat, and John Thune, a Republican from South Dakota, sent a letter to LaHood on Monday accusing the FAA of being “slow and disturbingly limited” in response to their questions. They suggested the FAA could divert money from other accounts, such as those devoted to research, commercial space transportation and modernization of the air-traffic control computers.


Others in Congress urged the Obama administration to postpone the furlough for at least 30 days.


In the past five years, the FAA’s operating budget has grown by 10.4 percent while the number of domestic commercial flights has fallen 13 percent.