By Mark Felsenthal

WASHINGTON (Reuters) - The U.S. air travel system faces widespread disruptions if automatic government spending cuts go into effect next week, Transportation Secretary Ray LaHood said on Friday in an effort to pressure congressional lawmakers to delay the cuts.

LaHood painted a dismal picture of delayed and canceled flights, shuttered control towers and airports, and irate air travelers from coast to coast if across-the-board spending cuts are allowed to take place under the process known as sequestration.

"Flights to major cities like New York, Chicago and San Francisco and others could experience delays of up to 90 minutes during peak hours," he told reporters at the White House. "Delays in these major airports will ripple across the country."

Some $85 billion in cuts are due to be applied across government programs on March 1 unless lawmakers act. The cuts were designed to be so onerous they would force a compromise over a broader deficit reduction package, but this has proven elusive.

President Obama has urged Congress to postpone the cuts for several months to let the White House and congressional Republicans hammer out a deficit-cutting deal. The president has given a series of speeches, echoed by his staff, stressing the economic damage the cuts would cause.

Republicans, who have argued that government overspending is a leading problem hurting the U.S. economy, have so far rebuffed the president's efforts. A number of Republican members of Congress have said that while the cuts may be painful, they could benefit the nation's finances in the long term.

LaHood, a former Republican U.S. congressional representative, acknowledged that the administration hoped his warnings might sway the views of his fellow party members.

"I would describe my presence here with one word: Republican," the former congressman from Peoria, Illinois said. "They're hoping that maybe I can influence some of the people in my own party."

LaHood said sequestration would lead to $1 billion in spending cuts at the Transportation Department, of which more than $600 million would be to the Federal Aviation Administration, which oversees U.S. air travel.

The "vast majority" the FAA's approximately 47,000 employees face furloughs of at least a day per pay period until the end of September, he said.

The government would also close more than 100 air-traffic control towers in places with light traffic like Boca Raton, Florida, Joplin, Missouri, and Hilton Head, South Carolina, LaHood said.

(Additional reporting by Roberta Rampton, Jeff Mason; Editing by David Brunnstrom)