As part of our continuing close consultations on shared security challenges, the President spoke to Prime Minister Cameron today regarding the events unfolding in Ukraine The leaders expressed their grave concern over Russia's clear violation of Ukrainian sovereignty and territorial integrity, and both noted that the current circumstances are unacceptable. Russia has already started to pay a cost for its actions, such as reducing investor confidence in Russia. The two leaders welcomed the military observer mission being undertaken by Organization for Security and Cooperation in Europe at the request of the Government of Ukraine. They also discussed support for the government of Ukraine as it works to stabilize its economy and makes preparations for elections in May. The leaders agreed to stay in close contact in the days ahead.
Barack Obama, Readout of the President's Call with Prime Minister Cameron of the United Kingdom Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/305444