The Obama administration expanded sanctions against Russia targeting two banks, two energy companies, Ukraine separatists and defense companies.
Ukranian region of Donetsk declared their decision to join Russia.
The G7 eapproves Kiev actions, stands for further sanctions against Russia.
On Sunday, voters in the Crimea region voted with overwhelming majority to separate from Ukraine to join Russia, as the region has an ethnic Russian majority and became part of Ukraine only 60 years ago.
Ukraine mobilizes its forces after Russian president claimed he had the right to invade in the neighbouring state.
Ukraine new government asked NATO for help as Russian troops entered the region of Crimea.