The option of moving some sliding events -- such as bobsleigh and luge -- to Nagano had been mooted when the International Olympic Committee (IOC) adopted a series of reforms this week allowing future Games hosts more flexibility in the sports they stage and where they stage them.
The reforms are aimed at making the Games more cost-effective and sustainable for bidding cities.
Although Pyeongchang has run into financial difficulties in its preparations for 2018, the president of the Games organising committee, Cho Yang-Ho, said the IOC reforms had come too late.
With test events due to begin in February 2016, Cho said there was no time to draw up new plans, and he vowed that the Pyeongchang event would meet its challenges.
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"We are developing solid legacy plans for post-Games use of the venues, as well as measures to control costs," he said.
The organising committee has asked the South Korean government to pay more toward the price of a new main stadium.
Relations between the two countries are at their lowest ebb for years, with their respective governments at loggerheads over a number of territorial and historical disputes.
"It is our stance that holding some competitions in (Japan) will be very difficult, given the public sentiment here," Shin told the KBS TV station earlier this week.