VATICAN CITY - U.S. Secretary of State Marco Rubio will meet Pope Leo at the Vatican on Thursday, in a potentially fraught encounter as U.S. President Donald Trump has continued a series of disparaging attacks ​on the Catholic leader over the Iran war.Rubio, who also serves as Trump's national security ‌adviser, was due ‌to arrive at the Vatican's Apostolic Palace around 11:15 a.m. for the ​visit, the first between the pope and a Trump cabinet official in nearly a year.The closed-door meeting is expected to last about a half-hour, after which Rubio will also meet the Vatican's ⁠top diplomat, Italian Cardinal Pietro Parolin.