US and Russian officials have begun talks in Saudi Arabia as Donald Trump pushes to broker a limited ceasefire that Washington hopes will mark the first step toward lasting peace in Ukraine.

Ukraine and Russia have agreed in principle to a one-month halt on strikes on energy infrastructure after Trump spoke with the countries’ leaders last week. But uncertainty remains over how and when the partial ceasefire would take effect – and whether its scope would extend beyond energy infrastructure to include other critical sites, such as hospitals, bridges, and vital utilities.