Washington DC, May 21 -- US Secretary of State Marco Rubio on Tuesday (local time) stated that Russia would be slammed with additional sanctions by Washington if Moscow fails to provide a formal proposal outlining its conditions for a ceasefire in the Russia-Ukraine conflict, as reported by Anadolu Agency.

Speaking before the Senate Foreign Relations Committee, Rubio said that such a delay from Russia would show Moscow's real intent to negotiate on the matter.

"It's our understanding that the Russians are going to write up terms for what they would require in order to reach a ceasefire that then would allow broader negotiations," Rubio told the Senate Committee as quoted by Anadolu Agency.

"We await those terms, and then I'll have a mu...