By Agence France-Presse
Pence had originally been due to shuttle to the APEC talks from the northern Australian city of Cairns rather than stay overnight in Port Moresby, which is hosting the gathering for the first time.
But the White House confirmed that Pence would instead spend the night in the Pacific island nation, shrugging off its reputation for violence and petty crime.
"Staying in PNG is better for the schedule and the office was able to make it work, from a logistical and security standpoint," a senior administration official told AFP.
The port city is effectively on lockdown with a heavy police presence and warships from the US, Australia and New Zealand patrolling offshore.
Due to security and a dearth of hotel rooms, most journalists and delegates are billetted on two hulking cruise ships moored in the harbour with ultra-tight security access.
Although the threat posed by terrorism in Papua New Guinea is considered minimal, the Melanesian country has developed a reputation for lawlessness.
Feared street gangs known as "raskols" have made carjackings common and the country has among the highest rates of rape and domestic violence in the world.
Pence's decision to stay in Papua New Guinea now puts him in the same boat as China's President Xi Jinping, whose delegation has locked down the Stanley Hotel where Chinese lanterns abound and a pagoda has been constructed in his honour.
Some of the leaders are thought to be staying at the Airways hotel -- "one of the world's most unique airport hotels", according to its website.
Hotel guests describe security arrangements at the Airways as "immense" even without the APEC summit, complete with shotgun-toting guards at the gates.
"But that is nothing compared with what we see now," a resident said on Saturday, citing snipers on the roof, parts of the hotel sealed off, road blocks and special clearance required for cars.