Foreign ministers from the G7 group of nations, including the United States, Britain and France, have condemned an increase in Russian troop numbers near its border with Ukraine and in the Russian-occupied region of Crimea.
"These large-scale troop movements, without prior notification, represent threatening and destabilizing activities," the joint statement released by Britain's foreign ministry said.
"We call on Russia to cease its provocations and to immediately de-escalate tensions in line with its international obligations," the statement added.