Glasgow is hosting the historic climate change summit in less than a week.
Up to 30,000 delegates and world leaders, including US president Joe Biden, are set to descend on the city for two weeks from October 31 to 14.
But the country is also just days away from potential industrial action on Scotland’s railways due to an ongoing dispute over pay and conditions.
The RMT rail union, which represents ScotRail workers who are planning to strike, said the latest pay offer was “pitiful.”
Speaking about the potential strikes ahead on BBC’s Good Morning Scotland programme, Graeme Dey said: “This is a situation that we have tried extremely hard to avoid.
“We find ourselves in a perplexing and deeply disappointing situation.”
The RMT said “a gun is being pointed at its head” after a Wednesday deadline was set for accepting a recent pay offer.
Mr Dey said with the country less than a week away from the climate change summit, the Scottish Government has had to focus on making alternate travel plans if the offer is not accepted by tomorrow.
He added: “RMT keep moving the goal post.
“If there are strikes during Cop26 then we have to prepare for that.
“Not just to move delegates, but for the wider travelling public who will be disrupted by this.
“We have contingency plans ready and we have to pivot towards implementing those plans in detail, and the deadline tomorrow was simply set to allow everyone to know where we stand so that we can inform the delegates, the travelling public, what will be on offer in the way of services next week.”
In response, RMT Scotland organiser Mick Hogg said the union would be available “morning, noon and night” to resolve the disputes, but added that the comments of the transport minister were “absolutely nonsense”.
“The goalposts were never there to be moved in the first place – we have been stonewalled for the last 18 months,” he said.
“No talks have ever took place, albeit we’ve been in a dispute for the last eight months on a separate dispute over rest day working where no trains have been running on a Sunday.
“No talks have ever took place, then all of a sudden because of Cop26, there’s a rush to get around the table in order to find a resolution to the current disputes.”
Mr Hogg added: “We remain available morning, noon and night, anytime, anywhere, in order to get a settlement – that’s our position.”
He said the sticking point was that “efficiency savings”, which he claimed would lead to job losses, were conditions of the most recent offer.
Rail services in Scotland have been crippled for months by strike action, with few trains running on Sundays.
Three other unions have since settled their disputes with ScotRail.
RMT are expected to strike throughut the duration of the climate change summit in Glasgow.