The White House said Tuesday that both Ukraine and Russia have agreed to stop using force in the Black Sea – a deal in principle that the Kremlin says comes with several conditions before it can be implemented.

Russia and Ukraine also agreed to "develop measures to implement the agreement to ban strikes against energy facilities in Russia and Ukraine," the White House said.

The deal was limited, and it was not clear when or how it would start. The Kremlin also demanded some Western sanctions be lifted first.

Putin suggested Ukraine be placed under a form of temporary administration to reach a settlement in the war, Russian news agencies reported.

The White House on Thursday dismissed Russia's Putin's suggestion that peace talks in Ukraine depend on it being governed by the UN while elections are held.

Moscow is pushing for tough concessions as it drives ahead on the battlefield in Ukraine—and talks are only going to get more difficult from here.