Moscow’s forces are three miles from Dnipropetrovsk, a province they have never invaded. If they cross in, the advance would be a morale blow to Ukraine and complicate any territorial negotiations.

The United States and Russia will appoint high-level teams to negotiate the end of the war in Ukraine and are working to reestablish diplomatic channels, US Secretary of State Marco Rubio said at the end of key talks that excluded Kyiv.

Russia, like U.S. President Donald Trump, covets Ukraine's natural resources - and on the ground its forces are closing in on a giant lithium deposit. Trump said this month he wants Kyiv to hand over large quantities of its critical minerals in return for U.