World News Update, what you need to know

Theresa May has become Britain's prime minister with the task of leading its complex divorce from the European Union, and quickly named leading "Brexit" supporters to key positions in her new government.

ELSEWHERE:

LONDON - Former London mayor Boris Johnson has been appointed as British foreign secretary in a surprise appointment by the country's new Prime Minister Theresa May.

ATHENS - Greece will be recruiting dogs to sniff out potential tax dodgers trying to take cash out of the crisis hit country, where mass bank withdrawals prompted capital controls last year.

WASHINGTON - US Republican presidential contender Donald Trump has called for the resignation of Supreme Court Justice Ruth Bader Ginsburg, describing her as mentally unfit after she lambasted him in a series of media interviews.

ROME - The death toll from a high speed train crash in southern Italy has risen to 27 after rescuers worked through the night to try to extract bodies from the tangled wreckage and continued their search in the morning.

LONDON - So many different tree species grow in the Amazon rainforest that it will take another 300 years to discover them all, scientists say.