Presidents Donald Trump and Xi Jinping have no shortage of difficult issues to cover when they sit down for talks Thursday at the White House. The leaders are tackling issues like trade irritants, artificial intelligence safeguards and the war in Iran. Trump wants China to use its influence with Iran, while Xi seeks a halt to U.S. arms sales to Taiwan. A fragile trade truce had been set to expire in November, but the two countries agreed Wednesday to extend it for two months.