"Without question, Europe cannot and will not accept the purported right of the strong who violates international law," she said in a pre-released copy of today's speech.
Chancellor Merkel said that 2014 had seen "what it means when the foundations of our European peaceful order are called into question, that is, the self-determination of a people".
"This is exactly what Russia is doing to Ukraine," said the German Chancellor, who has spearheaded European diplomacy with Russia amid the crisis and frequently spoken with Russian President Vladimir Putin.
"Europe has decided not to be divided, but more than ever to act as a single entity to defend its peaceful order and its values," she said.
Ukrainian President Petro Poroshenko said on Monday he would meet Putin, Merkel and French President Francois Hollande on January 15 in Kazakhstan to discuss ongoing peace efforts between Kiev and pro-Moscow rebels.