He later said four of the missing had been confirmed as dead.
According to his mother, Sullivan had been a pilot with Mountain Air since 2012, flying tour groups over the rugged wilderness of Alaska's Inside Passage, a popular cruise ship route. One passenger remains unaccounted for, it said. Ten people, all Americans, were injured.
In a statement, Princess Cruises said it had activated members of its Care Team to provide assistance to the families impacted. Trips cost about $260 each.
One plane, a de Havilland Otter seaplane operated by Taquan Air, was carrying 10 guests from the cruise ship as well as a pilot, returning from a tour of the nearby Misty Fjords National Monument.
AP reported that weather conditions in the area of the crash comprised high overcast skies with 9 miles per hour southeast winds.
The crash occurred about 13 kilometres from Ketchikan, near George Inlet. The planes came down about a mile-and-a-half (2.5km) apart with some of the debris field on land. The other, carrying 11 people landed in the water, but started to sink. Vessels searched the area from the water, John said.
The Washington DC-based investigative team from the National Transportation Safety Board is expected to arrive in Ketchikan on Tuesday afternoon, agency spokesman Peter Knudson said.
Ten other people were injured in the collision, he said.
The four passengers on the Royal Princess plane and one pilot were all confirmed dead, the release said. But an official said Alaska is extremely remote, and said it's "one of the most hard conditions" to operate in.
Global Affairs Canada did not immediately respond to requests for comment on the company's statement that the Canadian was among those missing. A second plane was carrying four people from the ship on an independent tour.
Jerry Kiffer of the Ketchikan Volunteer Rescue Squad said several of the passengers had been removed from the beach by the time his crews arrived on Monday.
The aircraft involved were a Beaver float plane and an Otter float plane.
The search continues for two missing people - including a Canadian - following Monday's mid-air float plane crash in Alaska.
Eleven people were inside Taquan Air's single-engine de Havilland Otter DHC-3 when it went down. The NTSB later determined that pilot error and lack of a formal safety program were behind the crash.
One of the planes was operated by Taquan Air, which said it has suspended all scheduled flights and is cooperating fully with investigators.
The Royal Princess cruise is now sailing on a seven-day "Voyage of the Glaciers" cruise that departed from Vancouver on May 11.