Local, state and federal officials invested in the Metrorail extension to Dulles International Airport committed Wednesday to working together to try to reduce the cost of the project and to come up with a viable financing plan within 30 days.

The agreement came after at least 20 regional leaders met with U.S. Transportation Secretary Ray LaHood in his Southeast Washington offices to break an impasse over the location of the Metro station planned for Dulles.

There was no resolution reached on the airport station. But participants said they emerged from the hour-long meeting confident that all parties are committed to making the 23-mile rail extension a success.

“Everybody wants this project to happen. We just have to have it happen in a financially viable way,” said Scott K. York, chairman of the Loudoun County Board of Supervisors. York (I) has been highly critical of the $3.5 billion cost of the second phase of the project. Loudoun supervisors recently asked staff members to determine the consequences of withdrawing county financial support from the project.

Charles D. Snelling, who leads the Metropolitan Washington Airports Authority board, called it a constructive meeting and a “good climate in which to begin our work.” LaHood, he said, “has all the partners working together.” LaHood declined to comment on the meeting.

At issue is the second phase of the rail line to the airport and into Loudoun County. The airports authority, which is managing the rail project, has been assailed by local, state and federal officials for its vote in April in favor of an underground station at Dulles. The authority approved the underground station with an eye toward convenience for airline passengers and preservation of views of the terminal.

Northern Virginia officials, concerned about the overall cost of the project, have urged the board to reverse course and choose a less expensive above
ground option.

LaHood, who offered to mediate, asked a smaller group of stakeholders to return to his office Friday. That group, according to participants, would look for cost savings in the second leg of the rail extension, try to resolve where the Dulles rail station should be located and develop a financing plan — all with the goal of reporting back to the larger group within 30 days.

The federal government has contributed nearly $1 billion to the first phase of the project. Critical to the financing of the second phase is the award of a federal loan through the Transportation Department. Several participants broached the topic with LaHood but said he was noncommittal.

Those seated around the table described the meeting as collegial. Even as stakeholders agreed to shrink the cost of the project, there appeared to be broad agreement, several participants said, that trying to stick to the original cost projection of $2.5 billion was unrealistic because the estimate was based on assumptions, not engineering.

Fairfax County Board of Supervisors Chairman Sharon Bulova (D) said she presented a strategy on behalf of Fairfax, Loudoun and Virginia for reducing the cost, particularly for commuters who use the Dulles Toll Road. Future toll revenue is expected to contribute more than half of the cost of the second phase.

Bulova said that she and other local partners share the airports authority’s interest in ensuring convenience for airline passengers who take Metro to Dulles but that they should look for less expensive alternatives to the underground station.