NEW : ` ` Business as usual is not an option , '' says NATO secretary general . Amid signs the uneasy standoff between pro-Russian and Ukrainian forces could ignite into bloody conflict -- a day after Moscow claimed Crimea as its own -- almost 300 armed pro-Russian supporters took over the naval base in Sevastopol , said Marina Kanalyuk , assistant to the commander of Ukraine 's navy fleet . NEW : ` The United States and Russia have agreed to a new framework for cooperation in the fight against terrorism that will be announced at the end of this week by President Barack Obama and Russian president Vladimir Putin ' Ukraine says prepared to evacuate military personnel and family members from Crimea . On visit to Baltic states , U.S. Vice President Joe Biden slams Russian `` aggression ''
NEW : ` ` Business as usual is not an option , '' says NATO secretary general . NEW : ` The United States and Russia have agreed to a new framework for cooperation in the fight against terrorism that will be announced at the end of this week by President Barack Obama and Russian president Vladimir Putin ' Ukraine says prepared to evacuate military personnel and family members from Crimea . On visit to Baltic states , U.S. Vice President Joe Biden slams Russian `` aggression ''