The New Jersey state government was forced to shut down at midnight on Friday, as the State Legislature remained locked in a standoff with Gov. Chris Christie that left them unable to agree on a budget plan.

The most immediate effect of the shutdown will be on those headed to state-run parks and beaches for the holiday weekend. Mr. Christie’s office indicated that those parks and beaches would be closed, although their municipal counterparts will remain open.

Mr. Christie declared a state of emergency and called for a special session of the Legislature for 11 a.m. Saturday. Essential government services were to continue operating.

Mr. Christie is demanding that the $34.7 billion budget negotiated by the Legislature, which is controlled by the Democrats, include a provision requiring that Horizon Blue Cross Blue Shield spend some of its reserve fund on public health initiatives — particularly his drug treatment initiative. Without that provision, Mr. Christie, a Republican, has threatened to veto any budget that lawmakers send him.