( CNN ) -- During the last four months , the people of Ukraine have been fighting for their freedom , independence and European path in a war started by Russia-backed terrorists and their accomplices . Ukrainian military forces suffer heavy losses in battles against terrorists equipped with the newest Russian weaponry . We 've seen reports of the pro-Russian thugs shooting women and children , cynically calling it a `` protection of the Russian-speaking population . '' The price we are paying to bring peace back to the regions of Donetsk and Luhansk in eastern Ukraine is too high . Ukrainian President Petro Poroshenko has proposed the decentralization of power as part of his peace plan . It means more freedom , more economic autonomy and more opportunities to use languages spoken in a particular community for every region . How rebels in Ukraine built up an arsenal capable of reaching the skies . Ukraine has also demonstrated its genuine willingness to resolve this crisis through negotiations and compromises . Our armed forces have shown exceptional restraint during their military operations in order to avoid casualties among peaceful civilians and prevent destruction of their towns and villages . Our unilateral cease-fire in the zone of the conflict had lasted from June 20 to June 30 , during which 27 Ukrainian servicemen , from all over Ukraine , were killed by the bandits . On July 17 we believe the terrorists fired at the Malaysia Airlines Boeing 777 , cutting short the lives of almost 300 people . This was a tragic wake-up call to the whole world . From now on Russian exporters of terrorism bring tragedy and tears to people across the planet -- from the Netherlands to Australia . Ukrainians , knowing too well the bitterness of loss , sincerely share grief with the families of the deceased . Our government is conducting , together with a team of international experts , a thorough investigation of the circumstances of this heinous act of terrorism . There is already incontrovertible evidence that the airliner was shot down by an anti-aircraft missile system that had arrived from Russia . When civilian planes are shot down . For the first time since 1983 , when a Soviet jet fighter deliberately shot down a South Korean Boeing 747 , Russia stands entangled in such a horrendous tragedy . We remember that an objective investigation of that catastrophe was made possible only 10 years later , after the USSR collapsed . We would not like to have to wait that long to learn the truth about the tragedy of MH17 . Indeed , the guilty must be promptly punished . We are encouraged with the growing understanding in both the West and the East of the nature of terrorism in eastern Ukraine . While U.S. senators and European Union ministers already consider designating the Donetsk People 's Republic and its Luhansk twin as terrorist organizations , we expect Russia to halt its support to terrorists . Since most of them are Russian citizens and `` former '' security service officers , we also urge Moscow to take them away from Ukraine . They must go home . Russian sponsorship of terrorism in Ukraine amply demonstrates that in the 21st century any regional conflict invariably poses a threat to global security . International and internal terrorism , as well as unbridled export of conventional and high-tech weaponry , have no regard for state borders , national sovereignty or human lives . Ukraine has been consistently advocating not only international control of nuclear weapons , but today we also stand for the creation of a universal mechanism for international control of conventional arms . We strive for a world based on the respect for international law and trust between nations . Join us on Facebook.com/CNNOpinion .
General Klimkin : With downing of MH17 , price of oil in eastern Ukraine already too high . Klimkin : Ukrainians know bitterness of war , share it with relatives of the deceased . He says the guilty must be promptly punished .