Britain and France have pulled out of preparatory talks due to be held in the coming days for the G8 summit in Sochi following Russia's decision to take military action in Ukraine.

The British foreign minister, William Hague, said the sovereignty and territorial integrity of Ukraine had been violated and called on Moscow to speak directly to the country's new leaders in Kiev.

Pressure is mounting on Vladimir Putin after the Russian parliament authorised the use of troops, but so far the president has ignored widespread international condemnation of his country's aggression.

Hague was due to attend discussions in the Black Sea resort paving the way for the G8 summit in June, but the UK is now suspending its co-operation with the process.

Speaking from RAF Northolt as he was about to board a plane to Kiev, Hague said: "We have to recognise the sovereignty and the territorial integrity of Ukraine has been violated and this cannot be the way to conduct international affairs and so, in addition to calling yesterday's emergency meeting of the UN security council, the United Kingdom will join other G8 countries this week in suspending our co-operation under the G8, which Russia chairs this year, including the meetings this week for the preparation of the G8 summit.

"We will keep our approach to further G8 meetings under review."

Ukraine's new prime minister, Arseniy Yatsenyuk, has called on Putin to pull back his troops, saying "we are on the brink of disaster", while the Nato secretary general, Anders Fogh Rasmussen, urged Moscow to calm the "dangerous" situation.

Hague, who will meet Ukraine's interim leaders, added: "I think we will see increasingly over the coming days the very strong concerns of many, many nations and I hope that that direct communication between the two countries will be able to take place.

"Our response is diplomatic and peaceful and it should be. That is our response but it will be a very united diplomatic response and not just from the western world, I think, but from many other countries in the world and that is something that Russia will have to think hard about."

Hague said Ukraine had previously insisted it would not escalate the situation and he would urge its new leaders to maintain that position during Sunday's talks in Kiev.

"It very much remains our view that they should not rise to provocations, they should not feed the tensions and so we call on both sides to ensure that there can be a reduction in tensions and the avoidance of conflict."

France has suspended participation in preparatory meetings ahead of the G8 meeting in Sochi, a source in President François Hollande's office said on Sunday.