IOC president Thomas Bach has told Ukraine that its calls for a boycott of the 2024 Paris Games over the possible participation of Russian competitors goes against Olympic "principles".

In a letter to the Ukrainian National Olympic Committee revealed on Thursday, Bach said Ukraine's efforts in "pressuring" other countries to boycott the 2024 Games was "extremely regrettable".

The International Olympic Committee said last month it was exploring a "pathway" to allow Russian and Belarusian competitors to take part in the Paris Olympics, under a neutral flag.

Ukraine has reacted furiously, threatening to pull out of the Games. Nordic and some eastern European countries have said they would join a boycott.

"Threatening a boycott of the Olympic Games which, as you inform me, the NOC of Ukraine is currently considering, goes against the fundamentals of the Olympic Movement and the principles we stand for," Bach said in the letter to Ukraine's Olympic chief Vadym Goutzeit.

Bach said the participation of Russian and Belarusian athletes "has not even been discussed in concrete terms yet".

"Therefore, your letter at this premature stage to your fellow NOCs, to the International Federations, IOC Members and to future Olympic hosts, pressuring them in an attempt to publicly influence their decision-making, has been perceived by the vast majority of them as, at the very least, extremely regrettable," Bach added.