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.
U.S. Secretary of State John Kerry was joined by British Foreign Secretary William Hague and Ukrainian Acting Foreign Minister Andrii Deshchytsia at a press conference in Paris, where the three leaders had convened for consultations, as provided in Article 6 of the memorandum.
Kerry read briefly from key sections of the memorandum that concern use of force and economic coercion against Ukraine, and agreed to in 1994 by Russia, the U.S., and the UK.
"... none of their weapons will ever be used against Ukraine except in self-defense or otherwise in accordance with the Charter of the United Nations.
"... refrain from economic coercion designed to subordinate to their own interest the exercise by Ukraine of the rights inherent in its sovereignty."
Kerry concluded that "there are very clear legal obligations that are at risk" by Russia's occupation of Ukraine's Crimean Peninsula, "and we're going to talk about those here this morning."
With regard to Russia's absence, Hague said "we will every diplomatic effort today to bring Russia and Ukraine into direct contact at ministerial level with the support of other nations." Ukraine, Deshchytsia said, is "looking very much forward that we will be also having consultations with Russia bilaterally and multilaterally."
Ukraine's acting foreign minister took to Twitter to express his appreciation for support from the memorandum partners, and noted that "All that's left, Russian reply."