Amtrak officials confirmed on Thursday that they were planning to close several tracks at Pennsylvania Station in New York this summer for major repairs, but the railroad’s chief executive refused to say how many tracks would be closed or for how long.

The decision to close tracks during busy weekdays will disrupt the lives of thousands of commuters who rely on the station. But during an announcement about the railroad’s repair plans, Amtrak’s chief executive, Charles W. Moorman, repeatedly declined to provide a specific number of tracks that would be closed or to say how disruptive the work would be for commuters.

A federal official who had been briefed on the plans said Amtrak was trying to limit the number of closings to about three or four tracks at once. Amtrak officials want to avoid the chaos that ensued this month when they closed eight of the station’s 21 tracks after a derailment, said the official, who was not authorized to discuss the railroad’s plans publicly.

On Thursday, Mr. Moorman said Amtrak wanted to consult with New Jersey Transit and the Long Island Rail Road, the other railroads that use the station, before disclosing details about the track closings.