TRENTON - The state Legislature's top Democrat says an overhaul of the New Jersey pension system won't fly without a guarantee from the governor that the state will begin paying its share.

Senate President Stephen Sweeney says he'll soon announce major pension changes that will hinge on Gov. Chris Christie agreeing to start paying into the system. Payments have been skipped or greatly reduced in recent years.

New Jersey's pension funds for government workers, teachers and police and firefighters are underfunded by $53.9 billion and at risk of going broke unless changes are made.

Christie has proposed pension changes that include raising the retirement age and rolling back a 9 percent increase in benefits.

AP wire services contributed to this report.