When the 85-year-old Japanese Emperor Akihito steps down on April 30, it will be the latest in a string of historic abdications that have included the pope and several monarchs.
Prime Minister Theresa May was to meet on Wednesday with the leader of Britain's main opposition party in a bid to thrash out a Brexit compromise just days before a deadline to leave the EU.
US President Donald Trump has praised European members of NATO for increasing their defense budgets in line with US requests, but urged them to pay more.