The little boy wandered off from his family and “in a split second, ran straight toward the 400ft cliff edge” of the Kilauea volcano, the park said.

“His mother, screaming, managed to grab him”, the park added in its statement, when the toddler was “just a foot or so away from a fatal fall”.

Park ranger Jessica Ferracane, who observed the incident said that she hopes sharing details of the incident will help “prevent future tragedies”.

Kilauea, on Hawaii’s Big Island, is one of the world’s most active volcanoes.

It routinely erupts, and the latest eruption began on 23 December with lava pictured gushing to the surface.

The eruption is continuing at a low level within a closed area of the national park, the USGS Hawaiian Volcano Observatory said in its latest update on Saturday.

The park said the incident happened on Christmas Day in a closed area of the park where families had gathered to watch the lava.

It was in an area overlooking the caldera – the large crater of the volcano – and the boy would not have survived the fall, Ms Ferracane said.

Park rangers said they want to remind visitors to stay on trail and out of closed areas, and to keep their children close.

“Those who ignore the warnings, walk past closure signs, lose track of loved ones, and sneak into closed areas to get a closer look do so at great risk.

“Ms Ferracane added: “Hopefully sharing the news will prevent future tragedies and near-misses.”

Flight 202 departed from Chicago’s O’Hare airport on Tuesday morning and landed at Maui’s Kahului airport in the afternoon.

A United Airlines said it remained unclear how or when the person got into the landing gear, which it said was only accessible from the outside of the Boeing 787-10 aircraft.

The company said it was working with law enforcement authorities on an investigation.

The deceased person has not been named.

In a statement, the police department told Hawaii News Now that it was conducting an investigation “regarding a deceased individual discovered on an incoming flight from the mainland this afternoon. At this time, no further details are available”.

The BBC has contacted the Maui Police Department for comment.

Hannah Kobayashi, 30, was seen on video obtained by US immigration officials crossing on foot into Mexico shortly after she landed in LA from Hawaii and deliberately missed her connecting flight to New York, officials said.In a news conference, officials said she appeared on the video to be safe and that no foul play is suspected. They described her as a “voluntarily missing person”.

The update comes amid a massive search after her family said she sent them cryptic and bizarre messages about her money and identity being stolen.

“The investigation has not uncovered any evidence that Kobayashi is being trafficked or is the victim of foul play,” said LAPD Chief Jim McDonnell.

“She is also not a suspect in any criminal activity. Additionally, the investigators noted that before departing Maui, Kobayashi expressed the desire to step away from modern connectivity.”

“We’ve basically done everything we can do at this point,” the chief added. “She’s left the country and in another nation now.”

Ms Kobayashi has been missing since 8 November. She was spotted at several spots around LA in the following days, before vanishing on 12 November.

Her family disputes the police’s assertion that she intentionally missed her connecting flight and continue to be concerned for her safety, according to The LA Times.

“The lack of communication surrounding some important details has left us feeling excluded from potentially crucial developments,” her sister, Sydni Kobayashi, said in a statement, according to the Times.

“However, we do remain hopeful and optimistic that the Los Angeles Police Department is doing everything in their power to assist us in locating Hannah.”

On 24 November, Ms Kobayashi’s father, who had travelled to California to aid in the search, was reported by police to have taken his own life near the LA airport.

Ryan Kobayashi, 58, was found dead from multiple blunt force traumatic injuries, according to the LA coroner’s office.

The trip is being billed as a stopover as part of a Pacific tour, but comes amid long-running tensions between the US and China and growing concerns about the possibility of conflict over Taiwan.

After arriving in Hawaii, Lai said war would have “no winners” and that “we have to fight together to prevent war”.

China’s foreign ministry said it “strongly condemns” the visit and that it had “lodged serious protests with the US”.

China considers Taiwan – which broke away in 1949 following the Chinese Civil War – to be part of its own territory, and opposes any diplomatic engagement with it by other countries.

The US has long maintained a deliberately ambiguous policy towards the island, declining to recognise its independence but maintaining informal relations with its government.

Speaking before his departure for Hawaii, Lai said the trip marked “the beginning of a new era of value-based diplomacy”.

“Democracy, prosperity and peace are the expectations of the people of Taiwan, and they are also the values that I, as president, must actively promote,” he said.

He said he wanted to show the world that Taiwan is “not only a model of democracy, but also a key force in promoting global peace, stability, and prosperity”.

Speaking at a dinner on Saturday attended by state officials, members of Congress, and Taiwanese residents of Hawaii, he added that a visit that day to Pearl Harbour – whose bombing by Japan in 1941 brought the US into the Second World War – had served as a reminder of “the importance of ensuring peace”.

“Peace is priceless, and war has no winners. We have to fight, fight together to prevent war,” he said.

The rest of the trip will see Lai visit Marshall Islands, Tuvalu, and Palau, the only Pacific island nations among the 12 countries that recognise Taiwan’s independence. He will also stop for one night in the US territory of Guam.

In a statement ahead of the trip, a spokesperson for the Chinese defence ministry said China would “firmly oppose official interaction with China’s Taiwan region in any form” and “resolutely crush” attempts secure Taiwanese independence.