Ukrainian troops have now withdrawn from the Crimean Peninsula.
The news comes as America and its allies are turning up the heat on Russia for its invasion and annexation of the region.
On Monday, President Barack Obama met with world leaders in an emergency session in the Netherlands.
At that meeting, the G-8 officially became the G-7 after world leaders agreed to suspend Russia's 15-year membership in the group.
The summit, originally scheduled to take place in June in Sochi, Russia, will now be held in Brussels without President Vladimir Putin.
"Europe and America are united in our support of the Ukrainian government and the Ukrainian people," Obama told reporters. "We're united in imposing a cost on Russia for its actions so far."
Nevertheless, Russia is beefing up its military presence in the region.
There are currently about 30,000 Russian troops along the border of eastern Ukraine, 10,000 of whom were added last week.
Meanwhile, for the first time, Russian Foreign Minister Sergey Lavrov met Monday with his Ukrainian counterpart to discuss the crisis.
It was the highest level meeting between the adversaries since the new Ukrainian government took power a month ago.