US President Donald Trump invoked Israel on Wednesday in defense of his plan to build a wall on the border with Mexico in order to stop illegal immigration. 'Just ask Israel about walls,' Trump said during a speech to law enforcement officers in Washington. 'Do walls work? Just ask Israel. They work, if it's properly done.' Prime Minister Benjamin Netanyahu sparked a diplomatic row with Mexico last month when he tweeted, 'President Trump is right. I built a wall along Israel's southern border. It stopped all illegal immigration. Great Success. Great idea.'