Under the 1994 Budapest Memorandum -- signed by Russia, Ukraine, the U.S., and the U.K. -- Ukraine is assured of protection from threats or use of force against its territorial integrity or political independence in exchange for giving up its nuclear weapons.
"On the order of the President of Ukraine Petro Poroshenko, the Ministry of Foreign Affairs of Ukraine has appealed to the signatories of the Budapest Memorandum to hold consultations in connection with the intervention by the regular Armed Forces of the Russian Federation on the territory of Ukraine," said Foreign Ministry spokesman Yevhen Perebyinis on Tuesday.
The request comes as the Ukrainian National Security and Defense Council released an estimate that there are between 10,000 to 15,000 Russian troops and rebels inside Ukraine.
Russia declined, explaining it "sees no reason for any consultations on the implementation of the memorandum," Perebyinis reported.
"We consider Russia's refusal of consultations on the Budapest Memorandum as yet another example of Russia's denial of its obligations and yet another confirmation of a course of action deliberately chosen by its leadership to destroy the current system of international law," Ukraine's Foreign Ministry asserted, adding "Ukraine will continue its efforts to obtain additional security guarantees and to consolidate the international community to counter Russian aggression."