US opposes ‘endless negotiations’ on Ukraine – Rubio

"The U.S. does not want negotiations between Russia and Ukraine to drag on indefinitely, Secretary of State Marco Rubio has said, stressing that Washington expects concrete results.
Rubio said the U.S. would examine the ceasefire proposals from Russia and Ukraine. 

“If those papers have ideas on them that are realistic and rational, then I think we know we’ve made progress,” he said." RT