UK and US urge their citizens to leave Ukraine

Russia could invade Ukraine "at any time" and American citizens should leave immediately, the US has warned. The statement has prompted countries around the world to issue fresh warnings to nationals in Ukraine. Also on the programme: Our Africa correspondent become the first journalist to reach the remote disputed Chagos archipelago in the Indian ocean - we'll hear from him. And a senior virologist warns that many countries are lifting Covid restrictions too quickly (Photo: Ukrainian President Volodymyr Zelenskiy attends special tactical training exercises held by police, the National Guard and security services. CREDIT: REUTERS/Irakli Gedenidze)