CHICAGO (WBBM/CBS) — U.S. Sen. Mark Kirk threw his support behind the plan to expand O’Hare International Airport on Friday, as Mayor Richard M. Daley called for completing the massive project despite concerns about bond ratings at O’Hare.

As WBBM Newsradio 780’s Craig Dellimore reports, Kirk said that it’s vital for the Chicago area’s economy that O’Hare complete a project to reconfigure its runway system to an east-west parallel layout.

LISTEN: Newsradio 780’s Craig Dellimore reports

The freshman senator pledged to secure $60 million in funding needed to keep the project moving forward.

The Chicago Tribune reported earlier this week that Moody’s has downgraded some of the bonds the Chicago Department of Aviation has used to help pay for the O’Hare Modernization Program and other endeavors.

Moody’s says it took the action primarily because the city has been unable to get financial support from the airlines.

As WBBM Newsradio 780’s John Cody reports, Mayor Daley said Friday that airport expansion projects have a 20-year lead time and that the project is being done to benefit travelers, not airlines.

LISTEN: Newsradio 780’s John Cody reports

“They agreed to do it at the beginning – American, United, everybody – when we first did it,” Daley said. “I mean, this is about 11 years ago or more, and now they disagree. But I’m sorry, but we don’t build the airport for those airlines. We build the airport for the passengers.”

Daley says if Chicago stops runway expansion now because of bond warnings, it will have to return to the beginning and add five years to the project.

United and American airlines have said that, while they continue to back new runways at O’Hare International Airport, sources have told the Tribune the airlines contend that the project as currently constituted is not fiscally responsible.

The airlines have balked at continuing with the remaining $3.7 billion of the expansion plan. They have also reportedly warned of legal action in regard to future bond sales.

Kirk said he and fellow U.S. Sen. Dick Durbin hope to bring the airlines back to the table.

“I think we’ve also listened to cost concerns during a recession, so the western terminal goes on a slower track,” Kirk said, referring to delayed plans to add western access to the airport. “But as a public leader, what I want to say is that it is critical for the future of our economy and jobs that the runway projects continue.”

Earlier this year, the City Council approved a plan to issue $1 billion in bonds for the O’Hare expansion project.

The project calls for building one new runway, extending another runway and relocating a third. A new northern runway opened in November 2008, and about 500 former homes and businesses in west suburban Bensenville are being demolished to make way for the expanded airport.