It follows Russia’s invasion of Ukraine on Thursday (24 February). The UK government has since barred all Russian scheduled carriers from flying to the UK, with Russia retaliating with similar measures.

Russia and Ukraine specialist Regent Holidays was among the first to act; it is contacting all clients booked on trips to Ukraine, Russia, Belarus and Moldova that are due to depart up to the end of May.

Cruise lines are also closely monitoring the situation; Saga last week proactively rerouted a sailing due to call in the Ukrainian port city of Odessa, while Viking has cancelled all 2022 Kyiv and Black Sea departures.

Ben Ittensohn, director of global sales for Explore, confirmed to TTG on Friday (25 February) the brand had withdrawn all departures to Ukraine, including its popular Chernobyl tour, until the end of 2022.

The operator has also cancelled all trips to Russia until 30 June due to the country’s decision to bar UK carriers from landing in the country or entering its airspace.

"We are in contact with our partners and tour leaders in Ukraine, and will support them by resuming travel when it is safe to do so," said Ittensohn.

"We are also rebooking all customers with flights booked with us to other destinations who were due to transit via Kyiv. We are contacting agents with affected customers booked with us in departure order."

Meanwhile, Chris Watkins, managing director of Real Russia, described the impact of the conflict on business as "irrelevant". "I hope and pray for a swift and peaceful resolution as soon as possible," he said.

"It is very early days, and while we had some cancellations yesterday (24February), we are continuing to receive enquiries and bookings, albeit at a reduced number."

Travellers who have booked with the Russia specialist for the spring, summer and beyond, have – according to Watkins – taken a "wait and see" approach.

"We are in constant touch with our partners on the ground and our customers currently in Russia, who advise there are no services affected by the current situation and everything is operating as normal," he added.

An Intrepid Travel spokesperson said the firm’s thoughts were with the people on the ground in Ukraine, including members of its own team, its tour leaders and their families who are based there.

The brand is not currently operating any tours that visit Ukraine or Russia. "We are in the process of contacting them and will assist them in any way we can," said the spokesperson. "We are continuing to monitor the situation closely, and are hopeful of a safe and peaceful path out of this crisis soon."

Regent Holidays brand manager Andrea Godfrey, who has spent time living in both countries and is the operator’s Russia and Ukraine specialist, said she was "truly saddened" by the events that have unfolded in recent weeks. "Needless to say, we are following these events extremely closely and are in touch with many friends on the ground in Kyiv and beyond," said Godfrey.

Balkan Holidays sales and marketing manager Chris Rand said: "We are monitoring the situation. I’m pleased to say it hasn’t affected bookings."