This is bbc news. welcome if you re watching here in the uk or around the globe. our top stories. president vladimir putin visits mariupol, the ukrainian city which was captured by invading russian forces last year. switzerland s biggest bank, ubs, is in advanced talks to buy all or part of its troubled rival credit suisse. donald trump says he suspects there are plans to arrest him on tuesday, he s called on his supporters to protest. former prime minister borisjohnson will publish evidence in his defence ahead of a grilling by mps over whether he misled parliament about covid rule breaking parties.