United States National Weather Service's Pacific Tsunami Warning Center said in a statement early Friday that tsunami waves have been observed following the huge earthquake that occurred in a remote area between New Zealand and Tonga, which may hit Hawaii.

The magnitude 7.8 quake struck the Kermadec Islands region at 9:28 a.m. Hawaiian time.

The agency said it is investigating whether the event poses a threat to Hawaii. If tsunamis are generated, the first waves would reach the Hawaiian Island chain at 4:35 p.m. Hawaiian time.

The agency issued a tsunami warning for American Samoa but then downgraded it to an advisory.

A warning means tsunamis with the potential to generate widespread inundation are expected or occurring.