KYIV (Reuters) – British Prime Minister Boris Johnson arrived in the Ukrainian capital on Tuesday to meet President Volodymyr Zelenskiy amid heightened tensions with Russia. “As a friend and a democratic partner, the UK will continue to uphold Ukraine’s sovereignty in the face of those who seek to destroy it,” Johnson said on Twitter ahead of landing. (Reporting by Peter Nicholls, writing by Guy Faulconbridge; editing by Michael Holden)