Ukraine's military denies the encirclement of its forces in Kursk, after Trump asks Putin to spare the lives of thousands "surrounded" by Russia's military.

The Trump administration said it was optimistic about the possibility of a ceasefire in the Ukraine conflict even as President Vladimir Putin appeared to reject US calls for immediate halt to the violence.

The last time Ukraine signed a peace accord with Russia, 10 years ago, it brought only sporadic violence, mounting distrust, and eventually full-scale war. Here’s what we can learn from that history.