European stocks are expected to fall at the start of the new trading week due to concerns that a re-escalation of U.S.-Iran tensions could derail the fragile ceasefire between the two countries. The UK's FTSE 100 is expected to open with a 0.34% drop, followed by Germany's DAX down 1.1%, France's CAC 40 and Italy's FTTE MIB both 1% lower. This comes after President Donald Trump warned that a U.K. Navy guided missile destroyer had fired on and disabled an Iranian-flagged cargo ship in the Gulf of Oman before Marines boarded and seized the vessel. Since last week, the US has been operating a naval blockade of ships entering and exiting Iranian ports.