President Biden said on Tuesday that Americans should decide for themselves whether to wear masks, undercutting efforts by his administration to urge Americans to keep wearing face coverings on airplanes, trains and buses even after a federal judge struck down a nationwide mask mandate on public transport.

The decision to wear a mask is “up to them,” Mr. Biden told reporters during a trip to New Hampshire to promote infrastructure spending.

The Biden administration intends to appeal the ruling, if the Centers for Disease Control and Prevention decides that extending the measure is necessary.

The patchwork of messaging contributed to confusion less than 24 hours after the ruling was handed down.