Speaking from RAF Northolt as he was about to board a plane to Kiev, the foreign secretary 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 cooperation 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.”
It comes as the newly appointed head of Ukraine’s navy has sworn allegiance to the Crimea region, in the presence of its unrecognised pro-Russian leader.
Rear Admiral Denis Berezovsky was only made head of the navy on Saturday, as the government in Kiev reacted to the threat of Russian invasion.
Russia’s troops have been consolidating their hold on Crimea, which is home to its Black Sea fleet.
Ukraine has put its army on full combat alert following the widespread deployment of Russian troops.
Its new prime minister Arseniy Yatsenyuk has called on the Russian premier to pull back his troops, warning “we are on the brink of disaster” while Nato secretary general Anders Fogh Rasmussen urged Moscow to calm the “dangerous” situation.