New Delhi, March 25 -- The United States said on Tuesday it has reached separate agreements with Ukraine and Russia to ensure safe navigation in the Black Sea and to implement a ban on attacks by the two countries on each other's energy facilities.

The agreements, if implemented, would represent the clearest progress yet towards a wider ceasefire that Washington sees a stepping stone towards peace talks to bring an end to Russia's three-year-old war in Ukraine.

Russia, however, said it could not trust Ukrainian President Volodymyr Zelenskiy and it could therefore only sign a Black Sea deal if Washington issued an "order" to him to respect it.

"We will need clear guarantees. And given the sad experience of agreements with just Kyiv, the...