Ukraine can keep fighting Russia for the rest of the year with European support, Poland's Foreign Minister Radoslaw Sikorski said on Sunday. "Ukraine can fight on its own with our European support for the rest of this year, and I think Putin has to take this into account," Sikorski told CNN in an interview. Asked if his impression after talking to the U.S. Secretary of State Marco Rubio was that Ukraine would be offered security guarantees by Washington, Sikorski said the best guarantee for Ukraine was its almost million-man army, resisting Russian aggression.